Optimization of a Dispersive Liquid-Liquid Microextration Method for Analysis of Chlorpyrifos in Urine Using the Chemometrics Method

Aims: The use of simple, low cost, high -efficiency extraction methods for sample preparation in the forensic toxicology has been considered. Nowadays, the chemometrics technique can be used to determine the influencing factors on the response to optimize extraction methods. The aim of this study was to design and optimize a dispersive liquid-liquid microextraction (DLLME) method for extraction of chlorpyrifos from the urine using a chemometrics method. Methods: A DLLME method for extraction of chlorpyrifos in urine sample was designed. Then, we used a Taguchi model for screening and investigating the role of effective factors on the extraction of chlorpyrifos from the urine. A central composite design (CCD) has been used to examine the relationship between these factors. After validation of the extracted data, chlorpyrifos was extracted from the urine using an optimized DLLME method and detected with the high performance liquid chromatography –photo diode array detector (HPLC-PDA) instrumentation. Results: The optimized DLLME-HPLC-PDA method was linear in the range of 0.5 to 4 μg / ml, and the R2 coefficient was calculated to be 0.9996. The limits of detection and quantification ​​were 0.08 and 0.25 μg/ml, respectively. The total recovery of the method was calculated as 95.6% Conclusion: Optimized DLLME-HPLC-PDA method can be used as a simple, fast, inexpensive, sensitive and precise method for analyzing chlorpyrifos in urine specimens in clinical and forensic toxicology laboratories.