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2017 Volume 45 Issue 9
2017, 45(9): 1259-1263
doi: 10.11895/j.issn.0253-3820.170251
Abstract:
The glycoproteins in the biological sample are low abundance and are susceptible to be inhibited and interfered by other non-glycoproteins. An enrichment step is usually required before the glycoprotein analysis, but the operation steps of conventional solid-phase-based glycoprotein enrichment methods are difficult to be compatible with the most classical enzyme-linked immune sorbent assay (ELISA) technique. In this study, a novel water-soluble dendrimer based boronic acid capture (DBC) material was developed using PAMAM 4.0 as the carrier and boronic acid as the affinity group. The method was applied to the detection of glycoproteins in human liver microsomes using ELISA. In this study, the DBC enrichment conditions were optimized by model glycoprotein, and then its sensitivity and anti-interference ability were investigated. This method was applied to the enrichment of glycoproteinsin human liver microsomal. The results showed that the enrichment selectivity of DBC for glycoprotein could be up to 100000 folds, and the enrichment signal of glycoprotein could be increased by 100 times. Therefore, the ELISA method using DBC as a novel enrichment material for glycoprotein had high sensitivity and selectivity in detection of biological samples with only one simple incubation step, which was useful for glycoproteins researches.
The glycoproteins in the biological sample are low abundance and are susceptible to be inhibited and interfered by other non-glycoproteins. An enrichment step is usually required before the glycoprotein analysis, but the operation steps of conventional solid-phase-based glycoprotein enrichment methods are difficult to be compatible with the most classical enzyme-linked immune sorbent assay (ELISA) technique. In this study, a novel water-soluble dendrimer based boronic acid capture (DBC) material was developed using PAMAM 4.0 as the carrier and boronic acid as the affinity group. The method was applied to the detection of glycoproteins in human liver microsomes using ELISA. In this study, the DBC enrichment conditions were optimized by model glycoprotein, and then its sensitivity and anti-interference ability were investigated. This method was applied to the enrichment of glycoproteinsin human liver microsomal. The results showed that the enrichment selectivity of DBC for glycoprotein could be up to 100000 folds, and the enrichment signal of glycoprotein could be increased by 100 times. Therefore, the ELISA method using DBC as a novel enrichment material for glycoprotein had high sensitivity and selectivity in detection of biological samples with only one simple incubation step, which was useful for glycoproteins researches.
2017, 45(9): 1264-1270
doi: 10.11895/j.issn.0253-3820.170205
Abstract:
A method for measuring 13C isotopic abundance of intracellular metabolites of Saccharopolysporaerythraea by ultra-high performance liquid chromatography (UPLC)-triple quadrupole mass spectrometry was established. First, the chromatographic conditions of UPLC were optimized, and then the MS conditions such as unique tube lens voltage, collision energy, and ion pair were optimized. On the bases of length of the parent and daughter ions carbon chains and whether the daughter ions contain 13C atoms, the one-to-one method, one-to-many method and SIM method were established for measuring 13C isotopic abundance. Then these methods were used to measure naturally labeled intracellular metabolite standards and 13C labeled samples, and according to the gap between the experimental value and the theoretical value, the best method was established for each metabolite of different characteristics. The results showed that one-to-one method was most effective for measuring the metabolites of daughter ions not containing 13C atoms represented by sugar phosphates, one-to-many method was the best for measuring the metabolites of both parent and daughter ions containing 13C short carbon chains represented by carboxylic acids, SIM method could play a role in measuring the metabolites of both parent and daughter ions containing 13C long carbon chains represented by coenzyme A. This method had a good measurement precision and could be applied to the measurement of Saccharopolysporaerythraea intracellular metabolites, which contributed to the consequent study of metabolic mechanism and the efficient expression of erythromycin.
A method for measuring 13C isotopic abundance of intracellular metabolites of Saccharopolysporaerythraea by ultra-high performance liquid chromatography (UPLC)-triple quadrupole mass spectrometry was established. First, the chromatographic conditions of UPLC were optimized, and then the MS conditions such as unique tube lens voltage, collision energy, and ion pair were optimized. On the bases of length of the parent and daughter ions carbon chains and whether the daughter ions contain 13C atoms, the one-to-one method, one-to-many method and SIM method were established for measuring 13C isotopic abundance. Then these methods were used to measure naturally labeled intracellular metabolite standards and 13C labeled samples, and according to the gap between the experimental value and the theoretical value, the best method was established for each metabolite of different characteristics. The results showed that one-to-one method was most effective for measuring the metabolites of daughter ions not containing 13C atoms represented by sugar phosphates, one-to-many method was the best for measuring the metabolites of both parent and daughter ions containing 13C short carbon chains represented by carboxylic acids, SIM method could play a role in measuring the metabolites of both parent and daughter ions containing 13C long carbon chains represented by coenzyme A. This method had a good measurement precision and could be applied to the measurement of Saccharopolysporaerythraea intracellular metabolites, which contributed to the consequent study of metabolic mechanism and the efficient expression of erythromycin.
2017, 45(9): 1271-1277
doi: 10.11895/j.issn.0253-3820.170307
Abstract:
N-Acetylcysteine (NAC) protects rats administrated with gadolinium-based contrast agents from renal injury, however, the underlying mechanisms remain unclear. A 1H NMR-based metabolomics approach coupled with OPLS-DA (orthogonal projection to latent structure with discriminant analysis) was used to analyze the effect of NAC on urinary metabolic changes for Chronic Renal Failure Rats administrated with Gd-DTPA (Gd-Diethylenetriamine pentaacetic acid). Combined with univariate analysis of integral area, the significantly changed metabolites were selected to screen out the potential metabolic disturbances that induced by Gd-DTPA and NAC. These researches may attribute to study of the protective effect of NAC from renal failure induced by gadolinium-based contrast agents. The disturbance of energy metabolism, urea cycle and kynurenine metabolism were observed from the CRF group. Gd-DTPA caused the reduction of urinary choline, TMAO, o-HPA, p-HPA, hippurate, glycine, nicotinate and taurine accompanied with the elevation of allantoin. Metabonomic recovery in the NAC group was observed, which implied that NAC protects rats with chronic renal failure from Gd-DTPA induced disturbances of gut microbiota metabolism, liver mitochondria metabolism and kynurenine metabolism. The replenishment of glutathione in cells and the recovery of urea cycle that caused by NAC may protect rats from oxidative damage and renal injury.
N-Acetylcysteine (NAC) protects rats administrated with gadolinium-based contrast agents from renal injury, however, the underlying mechanisms remain unclear. A 1H NMR-based metabolomics approach coupled with OPLS-DA (orthogonal projection to latent structure with discriminant analysis) was used to analyze the effect of NAC on urinary metabolic changes for Chronic Renal Failure Rats administrated with Gd-DTPA (Gd-Diethylenetriamine pentaacetic acid). Combined with univariate analysis of integral area, the significantly changed metabolites were selected to screen out the potential metabolic disturbances that induced by Gd-DTPA and NAC. These researches may attribute to study of the protective effect of NAC from renal failure induced by gadolinium-based contrast agents. The disturbance of energy metabolism, urea cycle and kynurenine metabolism were observed from the CRF group. Gd-DTPA caused the reduction of urinary choline, TMAO, o-HPA, p-HPA, hippurate, glycine, nicotinate and taurine accompanied with the elevation of allantoin. Metabonomic recovery in the NAC group was observed, which implied that NAC protects rats with chronic renal failure from Gd-DTPA induced disturbances of gut microbiota metabolism, liver mitochondria metabolism and kynurenine metabolism. The replenishment of glutathione in cells and the recovery of urea cycle that caused by NAC may protect rats from oxidative damage and renal injury.
2017, 45(9): 1278-1283
doi: 10.11895/j.issn.0253-3820.170179
Abstract:
A simple assay for detection of phospholipase C (PLC) activity was developed based on a fluorescence liposome probe using the Liss Rhod PE-loaded phospholipid liposomes. The liposome probe was prepared by the coassembly of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and fluorescent lipid (Liss Rhod PE). The probe showed very low background fluorescence due to fluorescence self-quenching effect of Liss Rhod PE. As the PLC enzyme selectively digested lipid, the Rhod fluorescence was recovered from its quenched state, leading to the sensitive detection of PLC. This assay provided a limit of detection (at a signal-to-noise ratio of 3) of 2 U/L for PLC. In the presence of PLC inhibitor, the fluorescent response of the sensor for PLC decreased, indicating that the assay could also be used for screening PLC inhibitors.
A simple assay for detection of phospholipase C (PLC) activity was developed based on a fluorescence liposome probe using the Liss Rhod PE-loaded phospholipid liposomes. The liposome probe was prepared by the coassembly of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and fluorescent lipid (Liss Rhod PE). The probe showed very low background fluorescence due to fluorescence self-quenching effect of Liss Rhod PE. As the PLC enzyme selectively digested lipid, the Rhod fluorescence was recovered from its quenched state, leading to the sensitive detection of PLC. This assay provided a limit of detection (at a signal-to-noise ratio of 3) of 2 U/L for PLC. In the presence of PLC inhibitor, the fluorescent response of the sensor for PLC decreased, indicating that the assay could also be used for screening PLC inhibitors.
2017, 45(9): 1284-1290
doi: 10.11895/j.issn.0253-3820.170281
Abstract:
A mathematical model of competition-type lateral flow immunoassay (LFIA) was developed to describe the dynamic process of LFIA. The competition-type LFIA was divided into two categories:TwA-competition-type LFIA and TnA-competition-type LFIA. On the basis of the developed model, the COMSOL software was exploited to simulate the dynamic process of LFIA. The simulation result demonstrated the relationships between the concentrations of substances on the test and control lines and the influence factors. In particular, the influence factors in the TwA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the position of the test line (5-20 mm). On the other hand, the influence factors in the TnA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the porosity. Experiment result showed that the developed model could be used to explore the influence of the parameters on the test results, and optimize the performance of LFIA.
A mathematical model of competition-type lateral flow immunoassay (LFIA) was developed to describe the dynamic process of LFIA. The competition-type LFIA was divided into two categories:TwA-competition-type LFIA and TnA-competition-type LFIA. On the basis of the developed model, the COMSOL software was exploited to simulate the dynamic process of LFIA. The simulation result demonstrated the relationships between the concentrations of substances on the test and control lines and the influence factors. In particular, the influence factors in the TwA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the position of the test line (5-20 mm). On the other hand, the influence factors in the TnA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the porosity. Experiment result showed that the developed model could be used to explore the influence of the parameters on the test results, and optimize the performance of LFIA.
2017, 45(9): 1291-1296
doi: 10.11895/j.issn.0253-3820.170090
Abstract:
To facilitate noninvasive diagnosis of anemia, high-performance and portable near infrared (NIR) spectrometer for human blood constituents was designed and fabricated based on linear variable filter (LVF). Meanwhile, the performance of support vector regression (SVR) model for quantitative analysis of human hemoglobin (Hb) was investigated. Spectral data were collected noninvasively from 100 volunteers by self-designed LVF-NIR spectrometer, then divided into calibration set, validation set 1 and 2. To establish a robust SVR model, grid search method was applied to optimize the penalty parameter and kernel function parameter c=5.28, g=0.33. Then, Hb levels in the validation 1 and 2 sets were quantitatively analyzed. The results showed that the root mean square error of prediction (RMSEP) were 10.20 g/L and 10.85 g/L, respectively, and the relative RMSEP (R-RMSEP) were 6.85% and 7.48%, respectively. The results indicated that the SVR model had high prediction accuracy to Hb level and adaptability to different samples, and could satisfy the requirements of clinical measurement. Based on the SVR algorithm, the self-designed LVF-NIR spectrometer has a wide application prospect in the field of non-invasive anemia diagnosis.
To facilitate noninvasive diagnosis of anemia, high-performance and portable near infrared (NIR) spectrometer for human blood constituents was designed and fabricated based on linear variable filter (LVF). Meanwhile, the performance of support vector regression (SVR) model for quantitative analysis of human hemoglobin (Hb) was investigated. Spectral data were collected noninvasively from 100 volunteers by self-designed LVF-NIR spectrometer, then divided into calibration set, validation set 1 and 2. To establish a robust SVR model, grid search method was applied to optimize the penalty parameter and kernel function parameter c=5.28, g=0.33. Then, Hb levels in the validation 1 and 2 sets were quantitatively analyzed. The results showed that the root mean square error of prediction (RMSEP) were 10.20 g/L and 10.85 g/L, respectively, and the relative RMSEP (R-RMSEP) were 6.85% and 7.48%, respectively. The results indicated that the SVR model had high prediction accuracy to Hb level and adaptability to different samples, and could satisfy the requirements of clinical measurement. Based on the SVR algorithm, the self-designed LVF-NIR spectrometer has a wide application prospect in the field of non-invasive anemia diagnosis.
2017, 45(9): 1297-1302
doi: 10.11895/j.issn.0253-3820.170279
Abstract:
The Fe-N-C composite catalyst was prepared by the thermal decomposition of the chelate precursors based on Fe(Ⅲ) central ions and o-phenylenediamine ligands. It was observed from the scanning electron microscopy that the crumpled carbon micro-and nano-sheets were intertwined to form a free-standing tremella-like 3D structure. The N2 adsorption/desorption experiments revealed that the composite contained ample micro-and meso-pores and had a specific surface area of 290 m2/g. Graphitic C and multi-crystal Fe3C as main components were confirmed by the X-ray diffraction, and N-doping in the general form of graphite N and pyridine N was also verified by X-ray photoelectron spectroscopy. The electrochemical measurement showed that the tremella-like Fe-N-C composite catalyzed oxygen reduction through a four-electron path in an alkaline solution, and its activity was comparable to the commercial Pt/C catalyst. After 2000 cycles, the limited current density of the Fe-N-C catalytic electrode only decreased less than 5%, and the half-wave potential shift negatively 5 mV, which suggested that the Fe-N-C composite catalyst had better catalytic stability than the commercially used Pt/C catalyst.
The Fe-N-C composite catalyst was prepared by the thermal decomposition of the chelate precursors based on Fe(Ⅲ) central ions and o-phenylenediamine ligands. It was observed from the scanning electron microscopy that the crumpled carbon micro-and nano-sheets were intertwined to form a free-standing tremella-like 3D structure. The N2 adsorption/desorption experiments revealed that the composite contained ample micro-and meso-pores and had a specific surface area of 290 m2/g. Graphitic C and multi-crystal Fe3C as main components were confirmed by the X-ray diffraction, and N-doping in the general form of graphite N and pyridine N was also verified by X-ray photoelectron spectroscopy. The electrochemical measurement showed that the tremella-like Fe-N-C composite catalyzed oxygen reduction through a four-electron path in an alkaline solution, and its activity was comparable to the commercial Pt/C catalyst. After 2000 cycles, the limited current density of the Fe-N-C catalytic electrode only decreased less than 5%, and the half-wave potential shift negatively 5 mV, which suggested that the Fe-N-C composite catalyst had better catalytic stability than the commercially used Pt/C catalyst.
2017, 45(9): 1303-1308
doi: 10.11895/j.issn.0253-3820.170154
Abstract:
The feasibility of frontal chromatography for determining the complexation stability constant KML and total mole of binding site Λo was demonstrated by the accuracy and precision binding experiments between metal ions (Cu2+, Ni2+ and Co2+) and chelating ligand (IDA), in which R2 > 0.98 and RSD <5%. To further prove the universality of the frontal chromatography, the changing rules of KML values between Cu2+, Ni2+, Co2+ and IDA, Asp, L-Glu were examined under NaAc-HAc, Na-PB and Tris-HCl buffer systems. The results showed that the binding strength of chelating ligands for metal ions followed IDA > Asp > Glu; binding strength of metal ions for chelate ligands followed Cu2+>Ni2+>Co2+; and the binding effect with NaAc-HAc buffer was the best. In aqueous solution, quantum computing of binding energy (ΔE) and gibbs free energy (ΔG) between chelating ligand and metal ion was performed at the M06/6-311++G (d, p) level. According to ΔE and ΔG, the binding rules between chelating ligand and metal ion were predicted theoretically. These rules were basically in agreement with above experimental results. The present work provided effective method for studying on binding characteristics of metal ions for aminocarboxyl chelating ligands, thus exhibited a good foundation for improving the stability of immobilized metal affinity chromatographic column and solving the leakage of metal ions from the column in the process of competitive elution.
The feasibility of frontal chromatography for determining the complexation stability constant KML and total mole of binding site Λo was demonstrated by the accuracy and precision binding experiments between metal ions (Cu2+, Ni2+ and Co2+) and chelating ligand (IDA), in which R2 > 0.98 and RSD <5%. To further prove the universality of the frontal chromatography, the changing rules of KML values between Cu2+, Ni2+, Co2+ and IDA, Asp, L-Glu were examined under NaAc-HAc, Na-PB and Tris-HCl buffer systems. The results showed that the binding strength of chelating ligands for metal ions followed IDA > Asp > Glu; binding strength of metal ions for chelate ligands followed Cu2+>Ni2+>Co2+; and the binding effect with NaAc-HAc buffer was the best. In aqueous solution, quantum computing of binding energy (ΔE) and gibbs free energy (ΔG) between chelating ligand and metal ion was performed at the M06/6-311++G (d, p) level. According to ΔE and ΔG, the binding rules between chelating ligand and metal ion were predicted theoretically. These rules were basically in agreement with above experimental results. The present work provided effective method for studying on binding characteristics of metal ions for aminocarboxyl chelating ligands, thus exhibited a good foundation for improving the stability of immobilized metal affinity chromatographic column and solving the leakage of metal ions from the column in the process of competitive elution.
2017, 45(9): 1309-1315
doi: 10.11895/j.issn.0253-3820.170230
Abstract:
Moss has high tolerance and accumulating capacity to heavy metal. In this study, the distribution of heavy metal elements in moss sampled from lead-zinc mine was analyzed by X-ray fluorescence spectrometry. The speciation of lead was analyzed by X-ray absorption near-edge spectroscopy. Research showed that the contents of Pb, Zn, Cd and As in the moss of the mining area were extremely high, and their maximum concentration were 1.06 mg/g, 1.23 mg/g, 30.5 μg/g, 13.2 μg/g, respectively. Besides, the shoots especially the new tissue of the moss were the major sites for accumulation and storage of heavy metals. The micro-distribution characteristics varied among Hypnum plumaeforme and Brachytheciumprocumbens, indicating the difference of different species of moss in absorption pathway, accumulation and tolerance mechanisms for heavy metal. Linear combination fitting results indicated that the main lead speciation in moss was lead phosphate (78%) and lead oxide (22%), which suggested that the precipitation of lead phosphate might be the main mechanism of tolerance for moss.
Moss has high tolerance and accumulating capacity to heavy metal. In this study, the distribution of heavy metal elements in moss sampled from lead-zinc mine was analyzed by X-ray fluorescence spectrometry. The speciation of lead was analyzed by X-ray absorption near-edge spectroscopy. Research showed that the contents of Pb, Zn, Cd and As in the moss of the mining area were extremely high, and their maximum concentration were 1.06 mg/g, 1.23 mg/g, 30.5 μg/g, 13.2 μg/g, respectively. Besides, the shoots especially the new tissue of the moss were the major sites for accumulation and storage of heavy metals. The micro-distribution characteristics varied among Hypnum plumaeforme and Brachytheciumprocumbens, indicating the difference of different species of moss in absorption pathway, accumulation and tolerance mechanisms for heavy metal. Linear combination fitting results indicated that the main lead speciation in moss was lead phosphate (78%) and lead oxide (22%), which suggested that the precipitation of lead phosphate might be the main mechanism of tolerance for moss.
2017, 45(9): 1316-1322
doi: 10.11895/j.issn.0253-3820.170348
Abstract:
The concentrations and distributions of trace metals and rare earth elements (REE) in sediment and mussel samples collected from the India Ocean hydrothermal area were analyzed. The metal correlation between organisms and sediments was investigated, and the ecological and chemical characteristics of REE were also explored. The results showed that, the trace metals in sediments were mainly Fe (96.6 mg/kg), Mn (1.14 mg/kg) and Zn (322.6 μg/kg), and Fe had high ratio of 98.15% by normalized calculation, which indicated that the available sediments in this studying hydrothermal area mainly consisted of iron ore substances. Trace metals and REE distributions all had good correlation between deep-sea sediments and deep-sea mussels, and the correlation coefficients were 0.991 for trace metals and 0.996 for REE. The contents and distributions of metal elements in deep-sea mussels were different from those in offshore mussels. The REE distributions in sediments and mussels showed obvious fractionation phenomenon, and the enrichment of LREE in mussels was significant. Through the REE patterns, Eu and Gd in sediments and mussels all showed anomalies, and Eu had a significant abnormal phenomenon in deep-sea sediments and deep-sea mussels. Besides, δEu values were 9.50, 10.68 and 0.23 in deep-sea sediments, deep-sea mussels and offshore mussels, respectively, and δCe were 2.21, 2.71 and 4.38, which showed that the enrichment sources of REE in offshore mussels and deep-sea mussels were different, and the REE in sediments and mussels from the India Ocean were homologous.
The concentrations and distributions of trace metals and rare earth elements (REE) in sediment and mussel samples collected from the India Ocean hydrothermal area were analyzed. The metal correlation between organisms and sediments was investigated, and the ecological and chemical characteristics of REE were also explored. The results showed that, the trace metals in sediments were mainly Fe (96.6 mg/kg), Mn (1.14 mg/kg) and Zn (322.6 μg/kg), and Fe had high ratio of 98.15% by normalized calculation, which indicated that the available sediments in this studying hydrothermal area mainly consisted of iron ore substances. Trace metals and REE distributions all had good correlation between deep-sea sediments and deep-sea mussels, and the correlation coefficients were 0.991 for trace metals and 0.996 for REE. The contents and distributions of metal elements in deep-sea mussels were different from those in offshore mussels. The REE distributions in sediments and mussels showed obvious fractionation phenomenon, and the enrichment of LREE in mussels was significant. Through the REE patterns, Eu and Gd in sediments and mussels all showed anomalies, and Eu had a significant abnormal phenomenon in deep-sea sediments and deep-sea mussels. Besides, δEu values were 9.50, 10.68 and 0.23 in deep-sea sediments, deep-sea mussels and offshore mussels, respectively, and δCe were 2.21, 2.71 and 4.38, which showed that the enrichment sources of REE in offshore mussels and deep-sea mussels were different, and the REE in sediments and mussels from the India Ocean were homologous.
2017, 45(9): 1323-1329
doi: 10.11895/j.issn.0253-3820.170217
Abstract:
A novel ionization enhancer, methylamine formate, was proposed for improving the detection sensitivity of triglyceride in edible oil by reversed phase liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). The commonly used isopropanol-acetonitrile-methanol-water and isopropanol-acetonitrile were selected as the mobile phase. By using a reversed phase C18 column, and taking the corn oil in isopropyl alcohol as sample solution, we compared methylamine formate with ammonium formate, as ionization enhancers, for their effect on the detection sensitivity of triglyceride by LC-ESI-MS after screening other different ionization enhancers, such as formic acid, acetic acid, ammonium formate, ammonium acetate, butyl formate, dibutylamine formate, triethylamine formate, diethylamine formate, methylamine formate, and ethylamine formate. The result indicated that, by using methylamine formate, the mass spectral peak response and the signal to noise ratio for trilinoleic glyceride component were 5 times higher than that of ammonium formate. The effect of the concentration of methylamine formate ionization enhancer, the flow rate of the mobile phase and the flow rate of nebulizing gas on the detection of methylamine formate were investigated. The concentration of triglyceride components in corn oil starting to form aggregates was similar in different mobile phases in the electrospray process according to measurement of the relationship between corn oil concentrations and the total ion chromatogram peak area of triglyceride. In particular, the peak area of trilinolein was linear with its concentration in the range of 7×10-7-2×10-4 mol/L (R2=0.9997), but increased slower in the higher concentration range. According to the experimental data, the mechanism for improvement of detection sensitivity of methylamine formate was suggested as that the addition of methylamine mono-charged ions with hydrophobic groups had lower solvation energy, which made the enriched addition ions easily evaporation from the droplet surface, thus improving the electrospray ionization efficiency. This method provided an effective way to improve the detection sensitivity of triglyceride in edible oil by LC-ESI-MS.
A novel ionization enhancer, methylamine formate, was proposed for improving the detection sensitivity of triglyceride in edible oil by reversed phase liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). The commonly used isopropanol-acetonitrile-methanol-water and isopropanol-acetonitrile were selected as the mobile phase. By using a reversed phase C18 column, and taking the corn oil in isopropyl alcohol as sample solution, we compared methylamine formate with ammonium formate, as ionization enhancers, for their effect on the detection sensitivity of triglyceride by LC-ESI-MS after screening other different ionization enhancers, such as formic acid, acetic acid, ammonium formate, ammonium acetate, butyl formate, dibutylamine formate, triethylamine formate, diethylamine formate, methylamine formate, and ethylamine formate. The result indicated that, by using methylamine formate, the mass spectral peak response and the signal to noise ratio for trilinoleic glyceride component were 5 times higher than that of ammonium formate. The effect of the concentration of methylamine formate ionization enhancer, the flow rate of the mobile phase and the flow rate of nebulizing gas on the detection of methylamine formate were investigated. The concentration of triglyceride components in corn oil starting to form aggregates was similar in different mobile phases in the electrospray process according to measurement of the relationship between corn oil concentrations and the total ion chromatogram peak area of triglyceride. In particular, the peak area of trilinolein was linear with its concentration in the range of 7×10-7-2×10-4 mol/L (R2=0.9997), but increased slower in the higher concentration range. According to the experimental data, the mechanism for improvement of detection sensitivity of methylamine formate was suggested as that the addition of methylamine mono-charged ions with hydrophobic groups had lower solvation energy, which made the enriched addition ions easily evaporation from the droplet surface, thus improving the electrospray ionization efficiency. This method provided an effective way to improve the detection sensitivity of triglyceride in edible oil by LC-ESI-MS.
2017, 45(9): 1330-1338
doi: 10.11895/j.issn.0253-3820.170319
Abstract:
A novel probe (DNSBN) towards biothiols on the basis of 4-hydroxynaphthalimide as fluorophores and 2, 4-dinitrobenzenesulfonyloxy group as specific recognition site was designed and synthesized. The result of absorption and fluorescence spectral analyses indicated that the probe had high sensitivity and selectivity towards cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), and the detection was not affected by other 17 kinds of natural amino acids. Meanwhile, it was confirmed that DNSBN was a ratiometric probe through the fluorescence titration experiment, and the fluorescent intensity at 555 nm had a high linear relationship with biothiols concentration in the range of 0-20 μmol/L. The detection limits (3σ) of Cys, Hcy and GSH were 25.9, 92.0 and 77.9 nmol/L, respectively. The absorption, emission and mass spectra indicated that biothiols could be engaged in nucleophilic substitution reaction with 2,4-dinitrobenzenesulfonate, which induced the sulfonic esters decomposed. With the departure of receptor unit, the d-PeT progress (donor-excited photoinduced electron transfer) was blocked with an obvious colorimetric and fluorescence change. Finally, HeLa cell imaging experiments verified that DNSBN had good biocompatibility and could be used to detect exogenous biothiols.
A novel probe (DNSBN) towards biothiols on the basis of 4-hydroxynaphthalimide as fluorophores and 2, 4-dinitrobenzenesulfonyloxy group as specific recognition site was designed and synthesized. The result of absorption and fluorescence spectral analyses indicated that the probe had high sensitivity and selectivity towards cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), and the detection was not affected by other 17 kinds of natural amino acids. Meanwhile, it was confirmed that DNSBN was a ratiometric probe through the fluorescence titration experiment, and the fluorescent intensity at 555 nm had a high linear relationship with biothiols concentration in the range of 0-20 μmol/L. The detection limits (3σ) of Cys, Hcy and GSH were 25.9, 92.0 and 77.9 nmol/L, respectively. The absorption, emission and mass spectra indicated that biothiols could be engaged in nucleophilic substitution reaction with 2,4-dinitrobenzenesulfonate, which induced the sulfonic esters decomposed. With the departure of receptor unit, the d-PeT progress (donor-excited photoinduced electron transfer) was blocked with an obvious colorimetric and fluorescence change. Finally, HeLa cell imaging experiments verified that DNSBN had good biocompatibility and could be used to detect exogenous biothiols.
2017, 45(9): 1339-1345
doi: 10.11895/j.issn.0253-3820.170158
Abstract:
The activated carbon with high specific surface area was prepared by carbonization with walnut shell as raw material and activation by potassium hydroxide. The surface of activated carbon was then modified by phenyltrimethoxysilane to prepare phenyl-bonded high specific surface area activated carbon adsorption material. The specific surface area and pore size distribution of phenyl-bonded activated carbon were measured by nitrogen adsorption method. The organic functional groups of the phenyl-bonded activated carbon, the chemical environment of the surface elements and the crystal structure were characterized by infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray powder diffraction method. The volatile organic compounds (VOCs) in the air were absorbed by a sampling tube filled with the adsorption material prepared here, then desorbed into carbon disulfide solution and detected by gas chromatography. The saturated adsorption capacities of phenyl bonded activated carbon to 7 kinds of VOCs (ethanol, acetone, hexane, ethyl acetate, tetrahydrofuran, 1,2-dichloroethane, benzene) were in the range of 129-216 mg/g. In the range of 0.05-2.50 mg/mL, there was a good linear relationship between the peak height of the 7 components and the concentration, and the detection limits were in the range of 0.92-3.60 mg/m3.
The activated carbon with high specific surface area was prepared by carbonization with walnut shell as raw material and activation by potassium hydroxide. The surface of activated carbon was then modified by phenyltrimethoxysilane to prepare phenyl-bonded high specific surface area activated carbon adsorption material. The specific surface area and pore size distribution of phenyl-bonded activated carbon were measured by nitrogen adsorption method. The organic functional groups of the phenyl-bonded activated carbon, the chemical environment of the surface elements and the crystal structure were characterized by infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray powder diffraction method. The volatile organic compounds (VOCs) in the air were absorbed by a sampling tube filled with the adsorption material prepared here, then desorbed into carbon disulfide solution and detected by gas chromatography. The saturated adsorption capacities of phenyl bonded activated carbon to 7 kinds of VOCs (ethanol, acetone, hexane, ethyl acetate, tetrahydrofuran, 1,2-dichloroethane, benzene) were in the range of 129-216 mg/g. In the range of 0.05-2.50 mg/mL, there was a good linear relationship between the peak height of the 7 components and the concentration, and the detection limits were in the range of 0.92-3.60 mg/m3.
2017, 45(9): 1346-1352
doi: 10.11895/j.issn.0253-3820.170125
Abstract:
A fluorescent molecular probe R6G-Flu was prepared by modifying fluorescein onto Rhodamine 6G. The probe could be used to recognize Al3+ specifically, and the detection limit could reach as low as 10-8 mol/L. After addition of Al3+ (10 μmol/L) to the probe, the solution showed a color change from colorless to pink, and green fluorescence was observed under the UV irradiation, which could be perceived by the naked eye. By measuring the fluorescence emission intensity of R6G-Flu at different pH, the probe could also be used to determine pH in acidic pH range (3.00-6.00) and basic pH range (8.00-10.50). The detection results of Al3+ and pH indicated that the R6G-Flu was a dual-functional fluorescent molecular probe.
A fluorescent molecular probe R6G-Flu was prepared by modifying fluorescein onto Rhodamine 6G. The probe could be used to recognize Al3+ specifically, and the detection limit could reach as low as 10-8 mol/L. After addition of Al3+ (10 μmol/L) to the probe, the solution showed a color change from colorless to pink, and green fluorescence was observed under the UV irradiation, which could be perceived by the naked eye. By measuring the fluorescence emission intensity of R6G-Flu at different pH, the probe could also be used to determine pH in acidic pH range (3.00-6.00) and basic pH range (8.00-10.50). The detection results of Al3+ and pH indicated that the R6G-Flu was a dual-functional fluorescent molecular probe.
2017, 45(9): 1353-1359
doi: 10.11895/j.issn.0253-3820.170216
Abstract:
Based on the AuNPs/Nafion composite membrane technology and immobilization of amino adenosine aptamer using carboxyl carbon nanotubes on the surface of a glassy carbon electrode, a electrochemiluminescence sensor was preparated. The sensor was characterized by cyclic voltammetry and electrochemical luminescence. The result showed that the sensor had a good stability and reproducibility. Adenosine and adenosine aptamer could form G-tetrahedral structure, leading a decrease of ECL intensity. Under the optimum experimental conditions, the relative ECL intensity showed a good linear relationship to the negative logarithm of adenosine concentration in the range of 1.0×10-11-1.0×10-7 mol/L, the linear equations was ΔIECL=-890lgC-5050 with a detection limit of 5.0×10-12 mol/L. The RSD was 2.7% in 11 times measurement of adenosine (1.0×10-10 mol/L). The recovery was 97.1%-110.0% in the determination of real adenosine sample.
Based on the AuNPs/Nafion composite membrane technology and immobilization of amino adenosine aptamer using carboxyl carbon nanotubes on the surface of a glassy carbon electrode, a electrochemiluminescence sensor was preparated. The sensor was characterized by cyclic voltammetry and electrochemical luminescence. The result showed that the sensor had a good stability and reproducibility. Adenosine and adenosine aptamer could form G-tetrahedral structure, leading a decrease of ECL intensity. Under the optimum experimental conditions, the relative ECL intensity showed a good linear relationship to the negative logarithm of adenosine concentration in the range of 1.0×10-11-1.0×10-7 mol/L, the linear equations was ΔIECL=-890lgC-5050 with a detection limit of 5.0×10-12 mol/L. The RSD was 2.7% in 11 times measurement of adenosine (1.0×10-10 mol/L). The recovery was 97.1%-110.0% in the determination of real adenosine sample.
2017, 45(9): 1360-1366
doi: 10.11895/j.issn.0253-3820.170256
Abstract:
A novel molecularly imprinted electrochemical sensor for direct detection of insulin was prepared based on epitope imprinting. C-Terminal polypeptide in insulin as template molecule was firstly self-assembled on the Au electrode. Then the molecularly imprinted polymer (MIP) was fabricated by electropolymerization with o-phenylenediamine (o-PD) as functional monomer on this Au electrode. After elution of template molecules by NaOH solution, the imprinting cavities were formed with the three-dimensional structure matched with the polypeptide in insulin molecules. The imprinting cavities could specifically recognize and rebind with insulin molecules. With K3[Fe(CN)6]/K4[Fe(CN)6] as a probe, the insulin was indirectly detected. There was a linear relationship between the response current and the insulin concentrations in the range of 1.0×10-14-5.0×10-13 mol/L, and the detection limit was 7.24×10-15 mol/L. The developed sensor exhibited good selectivity and stability, and could be applied to the determination of serum samples.
A novel molecularly imprinted electrochemical sensor for direct detection of insulin was prepared based on epitope imprinting. C-Terminal polypeptide in insulin as template molecule was firstly self-assembled on the Au electrode. Then the molecularly imprinted polymer (MIP) was fabricated by electropolymerization with o-phenylenediamine (o-PD) as functional monomer on this Au electrode. After elution of template molecules by NaOH solution, the imprinting cavities were formed with the three-dimensional structure matched with the polypeptide in insulin molecules. The imprinting cavities could specifically recognize and rebind with insulin molecules. With K3[Fe(CN)6]/K4[Fe(CN)6] as a probe, the insulin was indirectly detected. There was a linear relationship between the response current and the insulin concentrations in the range of 1.0×10-14-5.0×10-13 mol/L, and the detection limit was 7.24×10-15 mol/L. The developed sensor exhibited good selectivity and stability, and could be applied to the determination of serum samples.
2017, 45(9): 1367-1374
doi: 10.11895/j.issn.0253-3820.170261
Abstract:
To improve the sensitivity of molecularly imprinted electrochemical sensors, a Pd nanoparticles-modified molecularly imprinted polymer (MIP) film for the determination of trimethoprim (TMP) was developed by thermal polymerization with N, N'-methylene diacrylamide as a functional monomer, Pd nanoparticle as a dopant and ethylene glycol maleic rosinate acrylate as a crosslinking agent. The morphologies and chemical structures of the Pd nano-materials and the imprinted films were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The electrochemical properties of the nano-doped and undoped MIP sensors were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Results showed that the morphologies and chemical structures and the electrochemical properties of the doped molecularly imprinted sensor were remarkably different from those of the undoped imprinted sensor. Linear responses of the imprinted sensor to TMP were observed for concentrations ranging from 5.0×10-7 mol/L to 4.0×10-3 mol/L (R=0.9995), with a detection limit of 3.2×10-8 mol/L (S/N=3). The Pd nanoparticle doped MIP sensors exhibited high selectivity. The chronoamperometry showed that no interference from potential interfering species such as sulfamethoxazole, sulfadiazine, glucose, and urea were noted. The proposed electrochemical sensor was used to determine TMP in actual samples, with average recoveries of 96.8%-102.0%.
To improve the sensitivity of molecularly imprinted electrochemical sensors, a Pd nanoparticles-modified molecularly imprinted polymer (MIP) film for the determination of trimethoprim (TMP) was developed by thermal polymerization with N, N'-methylene diacrylamide as a functional monomer, Pd nanoparticle as a dopant and ethylene glycol maleic rosinate acrylate as a crosslinking agent. The morphologies and chemical structures of the Pd nano-materials and the imprinted films were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The electrochemical properties of the nano-doped and undoped MIP sensors were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Results showed that the morphologies and chemical structures and the electrochemical properties of the doped molecularly imprinted sensor were remarkably different from those of the undoped imprinted sensor. Linear responses of the imprinted sensor to TMP were observed for concentrations ranging from 5.0×10-7 mol/L to 4.0×10-3 mol/L (R=0.9995), with a detection limit of 3.2×10-8 mol/L (S/N=3). The Pd nanoparticle doped MIP sensors exhibited high selectivity. The chronoamperometry showed that no interference from potential interfering species such as sulfamethoxazole, sulfadiazine, glucose, and urea were noted. The proposed electrochemical sensor was used to determine TMP in actual samples, with average recoveries of 96.8%-102.0%.
2017, 45(9): 1375-1380
doi: 10.11895/j.issn.0253-3820.170289
Abstract:
Phthalate esters (PAEs) are commonly used plasticizers and have caused pollution to the environment due to their widespread use. Therefore, many countries have listed such compounds as a priority list of pollutants, and it is of great significance to establish an accurate analysis method for monitoring the pollution of PAEs in water. A method of solid phase membrane extraction combined with ultrasonic wave desortion-gas chromatography-mass spectrometer for analysis of PAEs in water was established in this study. The extraction and desorb conditions were optimized. In this study, the samples were ultrasonic wave desorbed for 7 min at bath temperature of 40℃ and ultrasonic powder of 50%. The detection limits (S/N>3) of this method were between 0.05 μg/L and 0.26 μg/L, the recoveries in different matrixes were between 76.2% and 112.3%, and the relative standard deviations were below 10%.
Phthalate esters (PAEs) are commonly used plasticizers and have caused pollution to the environment due to their widespread use. Therefore, many countries have listed such compounds as a priority list of pollutants, and it is of great significance to establish an accurate analysis method for monitoring the pollution of PAEs in water. A method of solid phase membrane extraction combined with ultrasonic wave desortion-gas chromatography-mass spectrometer for analysis of PAEs in water was established in this study. The extraction and desorb conditions were optimized. In this study, the samples were ultrasonic wave desorbed for 7 min at bath temperature of 40℃ and ultrasonic powder of 50%. The detection limits (S/N>3) of this method were between 0.05 μg/L and 0.26 μg/L, the recoveries in different matrixes were between 76.2% and 112.3%, and the relative standard deviations were below 10%.
2017, 45(9): 1381-1388
doi: 10.11895/j.issn.0253-3820.170194
Abstract:
A high throughput screening method based on QuEChERS purification and stable isotope dilution-liquid chromatography coupled to high resolution time-of-flight mass spectrometry was developed for the simultaneous rapid determination of 86 kinds of glucocorticoids (GCs) in cosmetics. The analytes were extracted by acetonitrile, and then the extracts were purified using an improved QuEChERS method. The chromatographic separation was performed on a novel multiple chromatographic retention mechanisms column of Poroshell 120 PFP (100 mm×2.1 mm, 2.7 μm) with gradient elution using 0.2% (V/V) acetic acid and acetonitrile as mobile phase. The accurate mass database of parent ions and mass spectra library of fragment ions of 86 GCs were established under positive ionization mode with electrospray ionization source. Based on the method described above, the qualitative identifications of the 86 GCs were accomplished without the contrast of standard substances. The results demonstrated that the linear range of this method was from 2 μg/L to 200 μg/L with good correlation coefficients of R2>0.99. The average recoveries of the 86 GCs ranged from 66.2% to 112.8%, and the relative standard deviation (RSDs) was 4.6%-13.9% at three different spiked levels. The limit of detection (LOD) and quantification (LOQ) were 0.006-0.015 mg/kg and 0.02-0.05 mg/kg, respectively. The method is simple, efficient, reliable and accurate, and is suitable for high throughput screening of 86 GCs added illegally in cosmetics.
A high throughput screening method based on QuEChERS purification and stable isotope dilution-liquid chromatography coupled to high resolution time-of-flight mass spectrometry was developed for the simultaneous rapid determination of 86 kinds of glucocorticoids (GCs) in cosmetics. The analytes were extracted by acetonitrile, and then the extracts were purified using an improved QuEChERS method. The chromatographic separation was performed on a novel multiple chromatographic retention mechanisms column of Poroshell 120 PFP (100 mm×2.1 mm, 2.7 μm) with gradient elution using 0.2% (V/V) acetic acid and acetonitrile as mobile phase. The accurate mass database of parent ions and mass spectra library of fragment ions of 86 GCs were established under positive ionization mode with electrospray ionization source. Based on the method described above, the qualitative identifications of the 86 GCs were accomplished without the contrast of standard substances. The results demonstrated that the linear range of this method was from 2 μg/L to 200 μg/L with good correlation coefficients of R2>0.99. The average recoveries of the 86 GCs ranged from 66.2% to 112.8%, and the relative standard deviation (RSDs) was 4.6%-13.9% at three different spiked levels. The limit of detection (LOD) and quantification (LOQ) were 0.006-0.015 mg/kg and 0.02-0.05 mg/kg, respectively. The method is simple, efficient, reliable and accurate, and is suitable for high throughput screening of 86 GCs added illegally in cosmetics.
2017, 45(9): 1389-1396
doi: 10.11895/j.issn.0253-3820.170173
Abstract:
A sensitive and effective method for determination of 16 kinds of antibiotics, including tetracycline, sulfonamide, fluoroquinolone and macrolide, in livestock and poultry manure using solid phase extraction-ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established. Aiming at the chemical properties and sample impurities of the target, the parameters such as mass spectrum conditions, types of extraction and ultrasonic power were optimized. Finally, the samples were extracted with 50% acetonitrile in phosphate buffer solution (pH=4) for three times, followed by ultrasonic steaming, centrifugal and rotary, dilution, and purified by SAX-HLB. After sample loading, the solid phase was washed with 10 mL of methanol-acetone (80:20, V/V), evaporated to near dryness at 35℃, and then re-dissolved and vortex mixed in 1 mL of 0.1% formic acid:methanol (1:1, V/V). The extracts were analyzed with UPLC-MS/MS and calculated by external standard method based on the monitored product ion. The results indicated that the average spiked recoveries of tetracycline, sulfonamide, fluoroquinolone and macrolide in manure were 56.4%-94.6% with relative standard deviations (RSDs) of 2.6%-19.8%, the LODs (S/N=3) were 0.01-2.50 μg/kg, and the LOQs (S/N=10) were 0.05-7.90 μg/kg. The method was simple with high stability, high sensitivity and good reproducibility, and suitable for the simultaneously determination of many antibiotics in animal and poultry manure.
A sensitive and effective method for determination of 16 kinds of antibiotics, including tetracycline, sulfonamide, fluoroquinolone and macrolide, in livestock and poultry manure using solid phase extraction-ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established. Aiming at the chemical properties and sample impurities of the target, the parameters such as mass spectrum conditions, types of extraction and ultrasonic power were optimized. Finally, the samples were extracted with 50% acetonitrile in phosphate buffer solution (pH=4) for three times, followed by ultrasonic steaming, centrifugal and rotary, dilution, and purified by SAX-HLB. After sample loading, the solid phase was washed with 10 mL of methanol-acetone (80:20, V/V), evaporated to near dryness at 35℃, and then re-dissolved and vortex mixed in 1 mL of 0.1% formic acid:methanol (1:1, V/V). The extracts were analyzed with UPLC-MS/MS and calculated by external standard method based on the monitored product ion. The results indicated that the average spiked recoveries of tetracycline, sulfonamide, fluoroquinolone and macrolide in manure were 56.4%-94.6% with relative standard deviations (RSDs) of 2.6%-19.8%, the LODs (S/N=3) were 0.01-2.50 μg/kg, and the LOQs (S/N=10) were 0.05-7.90 μg/kg. The method was simple with high stability, high sensitivity and good reproducibility, and suitable for the simultaneously determination of many antibiotics in animal and poultry manure.
2017, 45(9): 1397-1404
doi: 10.11895/j.issn.0253-3820.160885
Abstract:
A multi-residue analysis method was developed for the determination of 38 kinds of pesticides in nuts (almonds, peanuts, cashew nuts and walnuts) by QuEChERS-ultra-high performance liquid chromatography-tandem mass spectrometry. The pesticide residues were extracted with acetonitrile. The extract was cleaned up with PSA, C18 and Oasis PRiME HLB, and then analyzed by UPLC-MS/MS with multiple reaction monitoring (MRM) mode. External standard method was employed to quantify. The limits of detection (LODs, S/N=3) of this method were between 0.01 and 10 μg/kg, and the limits of quantitation (LOQs, S/N=10) were between 0.05-20 μg/kg. All of the tested pesticides showed good linear relationship (r>0.991). The practical samples were determined at three spiked levels and the average recoveries were between 51.0% and 126.0%. The RSDs were less than 20%. This method was simple, sensitive and accurate, and could be used for the routine analysis of pesticide residues in nuts.
A multi-residue analysis method was developed for the determination of 38 kinds of pesticides in nuts (almonds, peanuts, cashew nuts and walnuts) by QuEChERS-ultra-high performance liquid chromatography-tandem mass spectrometry. The pesticide residues were extracted with acetonitrile. The extract was cleaned up with PSA, C18 and Oasis PRiME HLB, and then analyzed by UPLC-MS/MS with multiple reaction monitoring (MRM) mode. External standard method was employed to quantify. The limits of detection (LODs, S/N=3) of this method were between 0.01 and 10 μg/kg, and the limits of quantitation (LOQs, S/N=10) were between 0.05-20 μg/kg. All of the tested pesticides showed good linear relationship (r>0.991). The practical samples were determined at three spiked levels and the average recoveries were between 51.0% and 126.0%. The RSDs were less than 20%. This method was simple, sensitive and accurate, and could be used for the routine analysis of pesticide residues in nuts.
2017, 45(9): 1405-1414
doi: 10.11895/j.issn.0253-3820.170324
Abstract:
The technique utilizes a laser focused on a small spot to create a micro-plasma on the sample surface. In recent years, laser-induced breakdown spectroscopy (LIBS) is a frontier analysis technique in spectrometric analysis, with the advantages such as real-time, online and non-contact analysis. The research and development of various instruments based on this technology has attracted great attention of researchers. In the article, we reviewed the research progress of LIBS instrument from the components and field equipment in recent years, mainly including portable LIBS, handheld LIBS and remote LIBS.
The technique utilizes a laser focused on a small spot to create a micro-plasma on the sample surface. In recent years, laser-induced breakdown spectroscopy (LIBS) is a frontier analysis technique in spectrometric analysis, with the advantages such as real-time, online and non-contact analysis. The research and development of various instruments based on this technology has attracted great attention of researchers. In the article, we reviewed the research progress of LIBS instrument from the components and field equipment in recent years, mainly including portable LIBS, handheld LIBS and remote LIBS.
2017, 45(9): 1415-1419
doi: 10.11895/j.issn.0253-3820.170327
Abstract:
The monitoring of total toxicity of water is of great importance to guarantee the safety of drinking water and estimate the level of water pollution from multiple pollutants. Here, we reported an online equipment for monitoring toxicity of water, where in-site cultured microorganisms were used as the test organism and respiratory inhibition of microorganisms was regarded as the toxicity response. A three-electrode electrochemical detector was integrated in the equipment, where an array electrode composed of microsized Pt disks, a Ag/AgCl (3 mol/L KCl) electrode and a gold wire were used as the working, reference and counter electrodes, respectively. The average respiratory inhibition ratios obtained with this equipment for 5.0, 10.0, 20.0 mg/L 3,5-dichlorophenol (DCP) were 24.4%, 48.9% and 59.2%, respectively. The equipment was further used for continuous online monitoring of the total toxicity of underground water, and successfully showed the toxicity alarm when challenged randomly by toxicity samples containing 5.0 mg/L DCP. The present results suggested the good promise of the equipment in online monitoring of water total toxicity.
The monitoring of total toxicity of water is of great importance to guarantee the safety of drinking water and estimate the level of water pollution from multiple pollutants. Here, we reported an online equipment for monitoring toxicity of water, where in-site cultured microorganisms were used as the test organism and respiratory inhibition of microorganisms was regarded as the toxicity response. A three-electrode electrochemical detector was integrated in the equipment, where an array electrode composed of microsized Pt disks, a Ag/AgCl (3 mol/L KCl) electrode and a gold wire were used as the working, reference and counter electrodes, respectively. The average respiratory inhibition ratios obtained with this equipment for 5.0, 10.0, 20.0 mg/L 3,5-dichlorophenol (DCP) were 24.4%, 48.9% and 59.2%, respectively. The equipment was further used for continuous online monitoring of the total toxicity of underground water, and successfully showed the toxicity alarm when challenged randomly by toxicity samples containing 5.0 mg/L DCP. The present results suggested the good promise of the equipment in online monitoring of water total toxicity.
