Journal of Analytical Toxicology

Chua,, S.C.;Lee,, B.L.;Liau,, L.S.;Ong,, C.N.

doi: 10.1093/jat/17.3.129pmid: 8336484

Abstract This paper describes a sensitive biological monitoring method for assessing exposure to styrene. Two major metabolites of styrene, mandelic acid (MA) and phenylglyoxylic acid (PGA), were measured in urine using reversed-phase high-performance liquid chromatography with a variable wavelength UV detector. The urine sample (200 µL) was saturated with 60 mg of sodium chloride and spiked with 20 µL of internal standard (O-methyl hippuric acid). Hydrochloric acid (6N HCI) was added for acidification followed by extraction with ethyl acetate. The extract (0.5 mL) was dried and reconstituted with the mobile phase. The mobile phase used was water-methanol (90:10) with 0.5% acetic acid. The filtrate (5 µL) was injected into the HPLC with a C18 column. The detection limits for MA and PGA were estimated to be 5 mg/L and 0.5 mg/L, respectively. The average recovery was 96% for MA and 84% for PGA. The between-days coefficients of variation for both metabolites were generally less than 11%. The average within-day variations were usually less than 5%. The method was verified with urine samples collected from workers exposed to styrene. Excellent correlations were observed between environmental styrene exposure and urinary MA (r=0.92) and PGA (r=0.85), determined by using the present method. The procedure is sensitive and reproducible, and can be applied to occupational health measurement of styrene exposure. This content is only available as a PDF.

Diosi, David, T.;Harvey, Dennis, C.

doi: 10.1093/jat/17.3.133pmid: 8336485

Abstract This paper describes refinements in procedures coupling methanolic extraction-precipitation of whole blood with subsequent screening for commonly encountered drugs of abuse using EMIT d.a.u, reagents on a Monarch Chemistry Analyzer. The automation capabilities inherent in the Monarch make batch processing of samples convenient and cost effective, The small sample volume requirement of the Monarch allows greater sensitivities and use of lower cutoffs than previously reported. Subsequent analysis of EMIT positives by GC/MS confirmed the presence of the indicated drugs of abuse 86.7% of the time. This content is only available as a PDF.

Martinez,, Francisca;Poet, Torka, S.;Pillai,, Radhakrishna;Erickson,, Julie;Estrada, Anthony, L.;Watson, Ronald, Ross

doi: 10.1093/jat/17.3.138pmid: 8336486

Abstract Two methods of drug detection, urinalysis and hair analysis, were compared with respect to the efficiency of identification of drug use in a population of men living on the Arizona-Mexico border. The standard curve of cannabinoids in urine was linear to 20 ng/mL. The GC/MS levels for all cannabinoids combined in urine were very similar to that obtained by radioimmunoassay (RIA), 91% concordance. Similar results were obtained from samples analyzed dually for the cocaine metabolite benzoylecgonine (BE) after spiking. As determined by RIA of urine, 74% of the subjects were positive for cannabinoids. The majority were in the range of 100–1000 ng/mg creatinine. The pattern of excretion of THC metabolites with respect to the verbally reported time of first use was fairly normal, with the peak rate of elimination 13–24 hours following the last reported use. Washed hair samples were extracted by overnight acid hydrolysis. Urine samples and neutralized hair extracts were analyzed for cocaine and BE by RIA. Of the hair samples, 55% contained cocaine/BE, as compared with only 4.3% of the urine samples. Most hair samples contained cocaine/BE In the range of 25–100 ng/sample (100 mg hair). All hair samples testing negative for cocaine/BE by RIA also tested negative by GCIMS, and four samples containing the highest amounts of cocaine and BE by RIA were similarly found to contain the highest amounts by GC/MS. Hair analysis, therefore, gives a wider window of detection of drug use than does urinalysis and shows merit in the confirmation of cocaine use in small clinical research studies. This content is only available as a PDF.

Smith, Norman, B.;Mathialagan,, Sumathy;Brooks, Klazina, E.

doi: 10.1093/jat/17.3.143pmid: 8336487

Abstract We report an inexpensive, sensitive paraquat quantitation method which is simple to perform. First, 5 mL of blanks, standards, or patient plasma are applied to 1-mL cyanopropyl extraction columns equipped with 15-mL reservoirs. The samples are drawn through the columns under vacuum, followed by a rinse with 15–20 mL of 0.1M NH4OH. Paraquat is eluted with 0.8 mL 0.1M HCI, which is then neutralized with 25 µL concentrated NH4OH. Sodium dithionite reagent (0.23M in 4M NaOH) is added (100 µL) and the color produced is measured by absorbance difference (A395 – A460). The assay is linear up to at least 4.351µM paraquat. The lower limit of quantitation is 0.23µM. Lipemic and icteric sera do not affect the method, but easily visible hemolysis elevates the concentrations measured by up to 0.7µM, independent of paraquat concentration. Equimolar amounts of diquat with paraquat, at paraquat concentrations from 0.4 to 4.0µM, elevate apparent paraquat concentrations by 0.08–0.28µM. At 0.632, 1.92, and 4.06µM paraquat, within-run coefficients of variation (CVs) were 6.27, 7.23, and 2.14%, and between-run CVs were 6.82, 8.42, and 4.43%, respectively. This content is only available as a PDF.

Poon,, Raymond;Villeneuve, David, C.;Chu,, Ih;Kinach,, Robert

doi: 10.1093/jat/17.3.146pmid: 8336488

Abstract An isocratic HPLC method has been developed for the direct measurement of d-glucaric acid in human urine. Pretreatment of urine with a boronic acid gel removed many interfering substances, including l-ascorbic acid and d-glucuronic acid. This method has a detection limit of 10µM d-glucaric acid (approximately 7 µmoles/g creatinine). The run-to-run precisions were 9.1% and 7.7% at urinary d-glucaric acid concentrations of 41 and 219 µmoles/g creatinine, respectively. Urinary d-glucaric acid concentrations in normal adults were found to cover a range of 15 to 89 µmoles/g creatinine (mean = 47 µmoles/g creatinine). The sensitivity of this method in detecting abnormal elevations in d-glucaric acid was demonstrated through its ability to measure changes in urinary concentrations with time after ingestion of d-glucuronolactone. This content is only available as a PDF.

Capacio, B., R.;Byers,, C.E.;Jackson,, T.K.;Matthews,, R.L.

doi: 10.1093/jat/17.3.151pmid: 8393119

Abstract A high-performance liquid chromatographic (HPLC) method for the determination of granisetron (GRN) in guinea pig plasma has been developed. Guinea pig plasma spiked with GRN was microfiltered, and the recovered filtrate was directly injected onto the column without any further cleanup procedures. Separation was achieved on a spherical silica column and GRN was detected at 305 nm. Approximately 800–900 injections were made without any evidence of column deterioration. For the standard curves, correlation coefficients ranged from 0.9978–0.9999, and the percent standard deviation (%SD) from the mean area under the curve (AUC) was calculated to be less than 10% for all concentrations, except for the lowest concentration (0.325 ng/µL, 11.3%). Between-day and within-day coefficients of variation (%CV) ranged from 4.9 to 9.5% and 3.6 to 7.6%, respectively. Percent errors for within-day test plasma samples were not greater than 8.2% of the expected concentration for all samples except for 1.125 ng/µL (−14.6%). The limit of sensitivity was found to be 0.019 ng/µL. Estimated recovery of GRN in the microfiltrate was calculated to be 58–59% and 78–81% in plasma and water, respectively. Stability studies indicated that repeated refrigeration and warming (for six days) of microfiltered GRN plasma samples produced no changes in GRN concentrations from day to day. However, microfiltered GRN plasma samples that were repeatedly frozen and thawed demonstrated erratic concentration changes from day to day. The precision, accuracy, and small sample requirements of this method indicate its utility for pharmacokinetic studies in small animals where sample volume may be restrictive. * The experiments described in this report were conducted according to the “Guide for Care and Use of Laboratory Animals,” National Research Council, NIH Publication No. 85-23, revised 1985. Portions of this work have been presented in poster form: C.E. Byers and B.R. Capacio, Federation of Amerian Societies for Experimental Biology (FASEB), April 1992. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the U.S. Army or the Department of Defense. This content is only available as a PDF.

Cone, Edward, J.;Dickerson,, Sandra;Paul, Buddha, D.;Mitchell, John, M.

doi: 10.1093/jat/17.3.156pmid: 8336489

Abstract Urine specimens collected after heroin, morphine, and codeine administration were tested by four commercial opiate immunoaasays (TDx, CAC, ABUS, and EMIT) and by GC/MS. Quantitative immunoassay results (morphine equivalents) were compared with results by GC/MS for total morphine, free morphine, or total codeine. Mean detection times for the broadly cross-reacting immunoassays (TDx, ABUS, and EMIT, 300 ng/mL cutoff) ranged from 15–44 hours following heroin and morphine administration and 33–54 hours following codeine administration. Detection times obtained with CAC (25 ng/mL cutoff) tended to be somewhat shorter as a result of the high selectivity of the antibody for free morphine. High correlations over a wide concentration range were obtained for TDx, CAC, and ABUS versus GC/MS, with specimens collected after heroin and morphine administration. EMIT showed a high correlation over a narrow concentration range (0–1000 ng/mL) with heroin and morphine specimens, but responses plateaued at higher concentrations. There was substantial variability in immunoassay responses with specimens collected after codeine administration. Generally, this study demonstrated that immunoassay responses for opiate urine testing can be used as a semi-quantitative guide for GC/MS confirmation; however, the presence of codeine increased variability and diminished the accuracy of the immunoassay response. This content is only available as a PDF.

Ellerbe,, P.;Long,, T.;Welch,, M.J.

doi: 10.1093/jat/17.3.165pmid: 8336490

Abstract The concentrations of amphetamine and methamphetamine in a new lyophilized human urine reference material (RM) were determined at the National Institute of Standards and Technology, in cooperation with the College of American Pathologists. In order to minimize the possibility of undetected bias, two different methods were developed. Both methods were based on isotope-dilution gas chromatography/mass spectrometry (GC/MS) with a deuterium-labeled standard. The first method used a solid phase extractor (SPE) to isolate the analytes, followed by forming the heptafluorobutyryl (HFB) derivatives for measurement by GC/MS. The second method used another kind of SPE to isolate the analytes, followed by forming the N-trifluoroacetyl-1-prolyl chloride (TPC) derivatives for measurement by GC/MS. The RM consists of three levels of amphetamine, three levels of methamphetamine, and a blank. For amphetamine, the concentrations are 291, 558, and 1081 ng/mL of human urine. For methamphetamine, the concentrations are 311, 573, and 1137 ng/mL of human urine. This content is only available as a PDF.

Joynt, Brian, P.

doi: 10.1093/jat/17.3.171pmid: 8336491

Abstract Triazolam has been a controversial drug since its appearance on world markets as a hypnotic more than ten years ago. Whole blood concentrations of triazolam as found in forensic cases are cited in several categories; that is, impaired driving: 17 cases; sexual assault: four cases; death due to drugs: 45 cases; drug-related death (drugs contributed to the death but were not the ultimate cause): 20 cases; drug-involved death (drugs were present but were not felt to be a contributing factor): six cases; miscellaneous: one case. The data was gleaned from a forensic toxicology database designed and used by the Forensic Toxicology Sections of the Royal Canadian Mounted Police (RCMP) laboratories in Canada. Triazolam concentrations from selected references are included for comparison. * Presented in part at the 38th Annual Meeting of the Canadian Society of Forensic Science (CSFS), held jointly with the Society of Forensic Toxicologists (SOFT) and the International Association of Bloodstain Pattern Analysis (IABPA) in Montreal, PQ, Canada, September 23–27,1991. This content is only available as a PDF.

Reimer,, Gerry;Suarez,, Agripina;Chui,, Y.C.

doi: 10.1093/jat/17.3.178pmid: 8336492

Abstract A standardbred mare was dosed with 40 mg yohimbine intravenously. Serum and urine samples were collected and analyzed for yohimbine using solvent extraction and reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection. Maximum yohimbine concentrations of 45 and 18 ng/mL were observed in serum and urine samples, respectively. Elimination was rapid, with half-lives of approximately 20 and 53 min observed for serum and urine, respectively. The presence of yohimbine in these samples was confirmed by liquid chromatography/mass spectroscopy (LC/MS/MS). This content is only available as a PDF.