Qi Gavin (Presenter)
CDPH
Authorship: Qi W. Gavin, Heng Wang, Jianwen She
| Short Abstract Previously, we have developed an LC/MS/MS method to analyze 13 environmental phenols in human urine. In this study, we expanded our method analyze triclocarban (TCC) along with previous analytes in human urine. Briefly, samples were processed using enzymatic de-conjugation of glucuronides, followed by solid phase extraction (SPE) on a C18 cartridge. Analytes in the concentrated eluate were separated by reversed-phase HPLC, detected by atmospheric pressure chemical ionization (APCI) MS/MS (QTRAP5500) in negative ion mode, and quantified by isotope dilution method. The method proved to be accurate, precise and without obvious matrix effects. The limits of detection are in the low ng/mL range. |
Long Abstract
Introduction
Triclocarban (TCC) is a polychlorinated phenol urea pesticide and is widely used as an antimicrobial agent in a variety of consumer and personal care products. TCC is considered a potential endocrine disruptor.
Method
This method measures triclocarban in human urine by high-pressure liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Urine samples were spiked with stable isotope-labeled internal standards and enzymatically de-conjugated overnight at 37ºC. The digested samples were then processed by SPE using C18 cartridges, and the eluents were evaporated and reconstituted with mobile phase immediately prior to the analysis using a reversed-phase HPLC-MS/MS system (API 5500 QTRAP, AB Sciex). Ionization of the analytes was carried out by atmospheric pressure chemical ionization (APCI). Quality control (low, medium and high), samples and blank samples were included in every analytical run to evaluate method accuracy and precision as well as background contamination.
Results
The method validated by the use of pooled human urine samples with excellent accuracy, precision and limits of detection. Inter-batch precision and accuracy assessments were performed at three levels which show good reproducibility (inter-day coefficient of variations ranging from 5.84 % to 9.44 %) and accuracy (spiked recoveries ranging from 85 % to 118 %). The detection limit is 0.1 ng/ml in 1 ml of urine for triclocarban.
Matrix effects on ionization efficiency were evaluated. However, the concentrations calculated after repeat dilution of QCL, QCM and QCH samples were in excellent agreement, suggesting limited or no effect on the concentrations measured due to matrix effects.
Conclusion
A sensitive HPLC/MS/MS method to determine triclocarban in human urine was developed. The method was validated using internal QC material samples and external QC, proficiency tests will be conducted.
This method will be used and applied for sample analysis for Biomonitoring California in program to evaluate the human exposure.
References & Acknowledgements:
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