title: Validation of a Rapid and Sensitive UPLC-MS-MS Method Coupled with Protein Precipitation for the Simultaneous Determination of Seven Pyrethroids in 100 µL of Rat Plasma by Using Ammonium Adduct as Precursor Ion.
abstract: United States Environmental Protection Agency has recommended estimating pyrethroids' risk using cumulative exposure. For cumulative risk assessment, it would be useful to have a bioanalytical method for quantification of one or several pyrethroids simultaneously in a small sample volume to support toxicokinetic studies. Therefore, in the present study, a simple, sensitive and high-throughput ultraperformance liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous analysis of seven pyrethroids (fenvalerate, fenpropathrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, cypermethrin and deltamethrin) in 100 µL of rat plasma. A simple single-step protein precipitation method was used for the extraction of target compounds. The total chromatographic run time of the method was 5 min. The chromatographic system used a Supelco C18 column and isocratic elution with a mobile phase consisting of methanol and 5 mM ammonium formate in the ratio of 90 : 10 (v/v). Mass spectrometer (API 4000) was operated in multiple reaction monitoring positive-ion mode using the electrospray ionization technique. The calibration curves were linear in the range of 7.8-2,000 ng/mL with correlation coefficients of ≥ 0.99. All validation parameters such as precision, accuracy, recovery, matrix effect and stability met the acceptance criteria according to the regulatory guidelines. The method was successfully applied to the toxicokinetic study of cypermethrin in rats. To the best of our knowledge, this is the first LC-MS-MS method for the simultaneous analysis of pyrethroids in rat plasma. This validated method with minimal modification can also be utilized for forensic and clinical toxicological applications due to its simplicity, sensitivity and rapidity.
authors.affiliation: Analytical Chemistry Laboratory and Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India sheelendra@iitr.res.in shilu1july@gmail.com.
authors.forename: Sheelendra Pratap
authors.initials: SP
authors.lastname: Singh
authors.affiliation: Analytical Chemistry Laboratory and Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India.
authors.forename: Nistha
authors.initials: N
authors.lastname: Dwivedi
authors.affiliation: Pharmacokinetics and Metabolism Division, CSIR-Central Drug Research Institute, Lucknow 226031, Uttar Pradesh, India.
authors.forename: Kanumuri Siva Rama
authors.initials: KS
authors.lastname: Raju
authors.affiliation: Pharmacokinetics and Metabolism Division, CSIR-Central Drug Research Institute, Lucknow 226031, Uttar Pradesh, India.
authors.forename: Isha
authors.initials: I
authors.lastname: Taneja
authors.affiliation: Pharmacokinetics and Metabolism Division, CSIR-Central Drug Research Institute, Lucknow 226031, Uttar Pradesh, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Wahajuddin
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry; D000818:Animals; D002138:Calibration; D011232:Chemical Precipitation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D057230:Limit of Detection; D008297:Male; D011722:Pyrethrins / Q000097:blood* / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D064751:Ammonium Compounds; D011722:Pyrethrins