Papain: a novel urine adulterant.

The estimated number of employees in the United Stated screened annually for illicit drugs is approximately 20 million, with marijuana being the most frequently abused drug. Urine adulterants provide an opportunity for illicit drug users to obtain a false-negative result on commonly used primary drug screening methods such as the enzyme multiplied immunoassay technique and the fluorescence polarized immunoassay technique (FPIA). Typical chemical adulterants such as nitrites are easily detected or render the urine specimen invalid as defined in the proposed SAMHSA guidelines for specimen validity testing based on creatinine, specific gravity, and pH. Papain is a cysteine protease with intrinsic ester hydrolysis capability. The primary metabolite of the psychoactive chemical in marijuana, 11-norcarboxy-Delta9-tetrahydrocannibinol (THC-COOH), was assayed by FPIA in concentrations ranging from 25 to 500 ng/mL, at pH values ranging from 4.5 to 8, over the course of 3 days with papain concentrations ranging from 0 to 10 mg/mL. FPIA analysis of other frequently abused drugs: amphetamines, barbiturates, benzodiazepines, cocaine, opiates, and phencyclidine, along with gas chromatography-mass spectrometry (GC-MS) of THC-COOH and high-pressure liquid chromatography-ultraviolet detection (HPLC-UV) of nordiazepam was performed in order to determine if the mechanism of urine adulteration by papain was analyte specific. Control and adulterated urine specimens (n = 30) were assayed for creatinine, specific gravity, and pH to determine if papain rendered the specimens invalid based on the proposed SAMHSA guidelines. There was a direct pH, temperature, and time-dependent correlate between the increase in papain concentration and the decrease in THC-COOH concentration from the untreated control groups (p < 0.01). The average 72-h THC-COOH concentration decrease at pH 6.2 with a papain concentration of 10 mg/mL was 50%. Papain did not significantly decrease the concentration of the other drugs analyzed with the exception of nordiazepam. GC-MS of THC-COOH and HPLC-UV of nordiazepam revealed a 66% and 24% decrease in concentration of the respective analyte with 10 mg/mL papain after 24 h at room temperature (approximately 23 degrees C). No adulterated specimens were rendered invalid based on the SAMHSA guidelines. Immediate FPIA analysis is suggested to minimize the interfering effects of papain with regards to primary drug screening.

Sevoflurane analysis in serum by headspace gas chromatography with application to various biological matrices.

Sevoflurane is a nonflammable general anesthetic administered by inhalation of vaporized liquid that rapidly partitions out of aqueous biological matrices into a gaseous phase because of its volatility and hydrophobicity. We describe a headspace analysis of sevoflurane that can be performed without the use of an expensive automated headspace analyzer. Sevoflurane standards (0-109 mg/L) and quality control specimens (12.2 and 72.9 mg/L) were prepared and quantitated on an intraday and interday basis. Headspace gas was manually injected (150 degrees C) with a 2.5-mL gas-tight syringe into a Perkin-Elmer model 8500 gas chromatograph equipped with a 6-ft x 2-mm i.d. glass column (100 degrees C) containing 0.2% Carbowax 1500 on Carbopak C packing with a flame-ionization detector (200 degrees C), which allowed for elution of the internal standard, 1-propanol (1.56 min), and sevoflurane (2.92 min). Linear regression of the peak-area ratios of sevoflurane to 1-propanol (6.38 g/L), versus the sevoflurane concentrations yielded an average intraday correlation coefficient of 0.989 (S.D. = 0.003, n = 5) and mean quality control specimen values of 14.19 mg/L (C.V. = 5.1%, n = 5) and 66.72 mg/L (C.V. = 3.3%, n = 5). The average interday standard curve correlation coefficient was 0.987 (S.D. = 0.01, n = 5), and the mean quality control specimen values were 12.22 mg/L (C.V. = 13.7%, n = 5) and 74.27 mg/L (C.V. = 8.7%, n = 5). The chromatographic method described produced accurate and reproducible results with a simple on-column headspace gas injection. This method allows for quantitation of sevoflurane in various biological matrices by chromatographic separation of the headspace gas in a sealed specimen container.

The distribution of sevoflurane in a sevoflurane induced death.

The distribution of sevoflurane (fluoromethyl 2,2,2,-trifluoro-1-(trifluoromethyl) ethyl ether) in blood, urine, liver, kidney, vitreous humor, and tracheal aspirate is presented from a subject with a sevoflurane induced death. Sevoflurane is a nonflammable general anesthetic administered by inhalation of vaporized liquid. Although general inhalation anesthetics have the potential to be fatal if not properly administered, the incidence of abuse is minute in comparison to other illicit drugs. Currently, there are no citations in the literature defining the body distribution of sevoflurane in a sevoflurane induced death. The decedent was found lying in a bed with an oxygen mask containing a gauze pad secured to his face. Three empty bottles and one partially full bottle of Ultane (sevoflurane) were found with the body in addition to two pill boxes containing a variety of prescription and non-prescription drugs. Serum, urine and gastric contents from the deceased were screened for numerous drugs and metabolites using a combination of thin layer chromatographic, colorimetric and immunoassay techniques. Analysis of biological specimens from the deceased revealed the presence of: amphetamine, caffeine, pseudoephedrine, nicotine, nicotine metabolite, and valproic acid. Sevoflurane concentrations were determined by headspace gas chromatography with flame ionization detection and revealed concentrations of 26.2 microg/mL in the blood, 105 microg/mL in the urine, 31.9 microg/mL in the tracheal aspirate, 86.7 microg/mL in the vitreous humor, 30.8 mg/kg in the liver, and 12.8 mg/kg in the kidney. The decedent had pathologies consistent with respiratory suppression including pulmonary atelectasis, pulmonary edema, and neck vein distention. The official cause of death was respiratory suppression by sevoflurane and the manner of death was unclear.

Determination of chromate adulteration of human urine by automated colorimetric and capillary ion electrophoretic analyses.

Various chemicals can be added to urine specimens collected for drug analysis to abnormally elevate ionic concentrations and/or interfere with either immunoassay urine drug-screening procedures or gas chromatographic-mass spectrometric confirmation techniques. One such adulterant, "Urine Luck" (formula 5.3), has been identified in our previous research to contain potassium dichromate. Screening of suspected adulterated specimens and confirmation of the adulterant are important for forensic drug screening. The application and comparison of automated colorimetric and capillary ion electrophoretic techniques for the detection, confirmation, and quantitation of chromate adulteration of urine specimens were the purpose of this investigation. Thirty-six urine specimens suspected of adulteration were analyzed for chromate by colorimetric analysis with diphenylcarbazide. Duplicate aliquots were analyzed for chromate by capillary ion electrophoresis. Results of the colorimetric chromate analyses revealed a mean chromate concentration of 929 microg/mL with a standard error of 177 microg/mL and a range of 30 to 5634 microg/mL. Results of the capillary ion electrophoresis chromate analyses revealed a mean chromate concentration of 1009 microg/mL with a standard error of 218 microg/mL and a range of 20 to 7501 microg/mL. The correlation coefficient between the capillary ion electrophoretic and colorimetric chromate results was r = 0.9669. Application of the automated diphenylcarbazide colorimetric technique provides rapid determination of chromate adulteration of a urine specimen. Capillary ion electrophoresis offers a separation technique to confirm the presence of chromate in suspected adulterated specimens. The excellent correlation between these methods substantiates their application to forensic testing as screening and/or confirmation techniques.