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An efficient and accurate method was developed for the simultaneous determination of 12 monohydroxylated polycyclic aromatic hydrocarbon metabolites in human urine. A 10.0-mL urine sample was hydrolyzed by enzyme and extracted using solid phase extraction. The metabolites were separated on an Acquity UPLC ® HSS T3 column (100 mm×2.1 mm, 1.8 μm) with a mobile phase comprising methanol and water. The analytes were detected by electrospray ionization (ESI)-MS/MS in negative mode and multiple reaction monitoring (MRM) mode. The linear ranges of the 12 metabolites were 0.04-20.0 μg/L with correlation coefficients above 0.99. The detection limits were in the range of 0.01-0.41 μg/L and the recoveries were 80.0%-105%. The intra-group relative standard deviations (RSDs) were less than 9.12% and the inter-group RSDs were less than 19.7%. This method was applied to the analysis of 100 urine samples and the results showed that the method was simple, sensitive and selective.

Objective: To develop a method for determination of creatinine in human urine by isotope dilution high performance liquid chromatography/tandem mass spectrometry., Methods: The urine samples were directly diluted 800 fold by mixed solution of methanol and water( 7 ∶ 3, V/V), and filtered with 0. 45 μm filter. The chromatographic separation was carried on an Atlantis Hilic Silica column( 2. 1 mm × 150 mm, 3 μm). Methanol and water mixture solution( 7 ∶ 3, V/V) were used as the mobile phases in an isocratic gradient. Mass detection was then conducted by electrospray ionization in positive ion( ESI+) mode and multiple reaction monitoring( MRM) mode. The concentration of creatinine was quantified by stable isotope labelled d3-creatinine internal standard. Standard reference material of urine creatinine was used to evaluate the accuracy of method, and then the uncertainty of this detection method was also evaluated., Results: The calibration curve of creatinine showed a good linear relationship in the range of 0. 31 μg/mL to 5. 00 μg/mL, and the related coefficient was 0. 999 9. The limit of detection( LOD) and limit of quantitation( LOQ) were 0. 003 mg/mL and 0. 011 mg/mL respectively, in real urine. Recoveries rates at two levels were 93. 9%-104. 0% and 90. 6%-93. 8%, with the relative standard deviation of 4. 4%-7. 6% and 4. 6%-7. 8%( n = 6), respectively. The creatinine concentration of standard reference material was in accordance with the reference value. The measurement uncertainty was mainly due to standard curves, recoveries rates and permissible error of instrument., Conclusion: The determination method is successfully applied to measure the concentration of creatinine in human urine with efficiency, accuracy and high sensitivity.

Objective: To simultaneously determine the four bisphenolic compounds (bisphenol F, bisphenol A, tetrachlorobisphenol A and tetrabromobisphenol A) in drinking water by liquid chromatography tandem mass spectrometry., Methods: 200 ml water sample was extracted by solid-phase extraction, eluted with methanol and analyzed by liquid chromatography tandem mass spectrometry under the MRM mode. The separation was carried out on a T3 column (2.1 mm x 150 mm, 3 μm)., Results: The limits of detection for the four bisphenolic compounds were in the range of 0.20 - 5.5 ng/L. The mean recoveries at the two spiked levels were 87.1% - 109.0% with the intra-day precision between 6.3% - 12.4% and inter-day precision between 4.5% - 15.4%. The method was applied for determination of 15 water samples., Conclusion: The method was sensitive, precise and accurate.

Objective: To develop on-line enrichment liquid chromatography tandem mass (LC-MS/MS) method for determination of S-phenylmercapturic acid (S-PMA) in urine., Methods: With d2-S-PMA added as internal standard, the urine samples were cleaned up and concentrated on Hypersil GOLD (20 mm x 2.1 mm x 12.0 microm) columns, and the targeted compounds were analyzed by HPLC-MS/MS under negative ion mode using Hypersil GOLD (50 mm x 2.1 mm x 3.0 microm) columns as analyzed columns. In the process of enrichment, the mobile phase is CH3OH: HCOOH (0.2%) = 5:95 (volume ratio), the flow rate is 1.50 ml/min. During the analysis, the mobile phase is CH3CN and HCOOH (0.2%) gradient elution, the flow rate is 350 microl/min., Results: The linear range was 0-500 ng/ml. The related coefficient was 0.9986. The detection limit was 8.0 ng/ml. The recoveries were 78.2%-84.5%. The relative standard deviation was 1.49% (n = 5)., Conclusion: The method uses internal standard method, it was used for determination of S-phenylmercapturic acid in the urine, sample don't need too much pretreatment, the sample volume to reduce, the organic solvent volume decrease. The method was simple, rapid, sensitive and accurate. It was for the detecting for S-phenylmercapturic acid in urine.

Objective: To establish a method to determine the presence and concentration of DEP, DMDTP, DEDTP, PNP, CMHC and TCPY organophosphorus pesticides metabolites in human urine by LC-MS/MS., Method: 2.0 ml of urine was enzymatically hydrolyzed in water bath 37 degrees C for 4 hours, then the urine samples were solid-phase extracted by Oasis HLB and eluted with methanol, after centrifugation and concentration the urine samples were separated on waters symmetry C18 5 microm (2.1 mm x 150 mm) column with ammonium acetate buffer solution acetonitrile-water as mobile phase to constant gradient elution. Electrospray ionization source (ESI) was applied and operated in positive ion mode, and multiple reaction monitoring (MRM) mode was adopted., Results: Within concentration ranging from 0 - 1000 ng/ml the correlation coefficient for 5 compounds of 6 were greater than 0.990, recoveries were between 79% - 130%, RSD < 8.2%. The RSD of intra-day and inter-day were less than 15% (n = 6)., Conclusion: The procedure of samples collection is simple. This is a accurate and specific method for testing organophosphorus pesticides metabolites in human urine.

Objective: To establish the method to determine the presence and concentration of 8 organophosphors pesticides in serum by LC/MS/MS., Method: The serum samples were extracted by ethyl acetateether and then separated on C18 5 microm (2.1 mm x 150 mm) column with pH = 3.5 acid-ammonium acetate buffer solution, methanol--water as mobile phase to mixed gradient elution. Electro-spray ionization source (ESI) was applied and operated in positive ion mode, and multiple reaction monitoring(MRM) mode was adopted., Result: Within concentration ranging from 0-1000 ng/ml the correlation coefficient for each compound was greater than 0.990, recoveries were between 95%-129%, RSD < 7.9%. The RSD of intra-day and inter-day were less 12% (n = 6)., Conclusion: The procedure of preparing serum samples is sample and the result of this method is efficient, accurate and specific.

Objective: To establish a method of determining the presence and concentration of 16 kinds of organophosphorus pesticides in serum by GC/MS/MS., Method: The parent ions of each pesticide was detected by running GC/MS in a full scan mode, and the peak areas and the ratio of signal to noise of each product ion were compared by setting different CID voltages. The CID voltage for each parent ion was optimized and determined. Serum samples were solid-phase extracted by Oasis HLB and eluted with ethyl ether after being concentrated and made to constant volume with ethyl ether, and then were tested by GC/MS/MS., Results: The correlation coefficient for each compound in the range of 0 - 1000ng/ml was greater than 0. 990. Recoveries of standard addition were 75% - 129% ,RSD < 10%. The intra-day and inter-day RSD was less than 15% (n = 6). The limits of quantification were less than 2ng/ml except for dichlorovos (55ng/ml)., Conclusion: GC/MS/MS assay is sensitive and accurate for the determination of pesticides in serum.

Objective: To develop a method for determining 11 kinds of phthalate metabolites in urine simultaneously., Methods: The phthalate metabolites in human urine samples were hydrolyzed by glucuronidase, and then were concentrated by solid-phase extraction and eluted by methanol/acetonitrile (1 : 1, V/V). After chromatographic separation on phenyl column, the analytes were analyzed qualitatively and quantitatively under MRM mode., Results: The limits of detection (LOD) for the eleven kinds of phthalate metabolites were in the range of 0.13 - 2.27 ng/ml. The mean recoveries at the two spiked levels were 67% - 108%, with the relative standard deviation (RSD) of less than 12%., Conclusion: The method can be used to determine the residues of eleven kinds of phthalate metabolites in urine accurately and sensitively.

Objective: To develope the determination methods for bisphenol A in drinking water system components., Methods: 30 samples were quantitatively analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS)., Results: Bisphenol A was linear in the range 0-100 ng/ml and the linear correlation coefficient reached 0.9994. The minimum detection limit was 5 microg/kg. The spiked recoveries were from 90% to 99%, and the RSD were between 1.8 -5.0%. Bisphenol A was measured in nine out of thirty samples. The detected ratio was 30% and the maximum was 1.82 mg/kg., Conclusion: The method was quick, sensitive and specific.