Simultaneous analysis method for GHB, ketamine, norketamine, phenobarbital, thiopental, zolpidem, zopiclone and phenytoin in urine, using C18 poroshell column

Abstract

Date-rape drugs have the potential to be used in drug-facilitated sexual assault, organ theft and property theft. Since they are colorless, tasteless and odorless, victims can drink without noticing, when added to the beverages. These drugs must be detected in time, before they are cleared up from the biofluids. A simultaneous extraction and determination method in urine for GHB, ketamine, norketamine, phenobarbital, thiopental, zolpidem, zopiclone and phenytoin (an anticonvulsant and antiepileptic drug) with LC-MS/MS was developed for the first time with analytically acceptable recoveries and validated. A4 steps liquid-liquid extraction was applied, using only 1.000 mL urine. A new age commercial C-18 poroshell column with high column efficiency was used for LC-MS/MS analysis with a fast isocratic elution as 5.5 min. A new MS transition were introduced for barbital. 222.7 > 179.8 with the effect of acetonitrile. Recoveries (%) were between 80.98-99.27 for all analytes, except for GHB which was 71.46. LOD and LOQ values were found in the ranges of 0.59-49.50 and 9.20-80.80 ngmL(-1) for all the analytes (except for GHB:3.44 and 6.00 mu gmL(-1)). HorRat values calculated (between 0.25-1.21), revealed that the inter-day and inter-analist precisions (RSD% <= 14.54%) acceptable. The simultaneous extraction and determination of these 8 analytes in urine is challenging because of the difficulty arising from the different chemical properties of some. Since the procedure can extract drugs from a wide range of polarity and pK(a), it increases the window of detection. Group representatives from barbiturates, z-drugs, ketamine, phenytoin and polar acidic drugs (GHB) have been successfully analyzed in this study with low detection limits. The method is important from the point of determining the combined or single use of these drugs in crimes and finding out the reasons of deaths related to these drugs. (C) 2016 Elsevier B.V. All rights reserved.