Validation of a headspace solid-phase microextraction-GC-MS/MS for the determination of ethyl glucuronide in hair according to forensic guidelines
ABSTRACT The analysis of ethyl glucuronide (EtG) in hair is a powerful tool for chronic alcohol abuse control because of the typical wide detection window of the hair matrix and due to the possibility of segmentation, allowing evaluation of alcohol consumption in different periods. Additionally, EtG in hair is often the only diagnostic parameter of choice for alcohol abuse when other clinical parameters such as ALT, AST, gammaGT and CDT (asialotransferrin and disialotransferrin) are in the normal range and EtG in urine negative. In this paper, we describe the development, optimization and validation of a new method based on hair extraction with water, clean-up by solid phase extraction (SPE), derivatization with heptafluorobutyric anhydride and headspace solid-phase microextraction (HS-SPME) in combination with GC-MS/MS according to forensic guidelines. The assay linearity of EtG was confirmed over the range from 2.8 to 1000 pg/mg hair, with a coefficient of determination (r(2)) above 0.999. The LLOQ was 2.8 pg/mg and the LLOD was 0.6 pg/mg. An error profile calculated according to the "Guide to the Expression of Uncertainty in Measurement" (GUM) at 99% confidence intervals for the range 5-750 pg/mg hair did not exceed 10%. This range corresponds to more than 98% of the positive samples analysed.
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- "Their subjects consumed a fixed daily amount of alcohol, and this helped to define the lower end of the continuum. Agius and colleagues  recently reported a headspace solid phase microextraction method in combination with a GC/MS/MS (gas chromatography/ tandem mass spectrometry) procedure to measure hair EtG. "
ABSTRACT: Widespread concern about illicit drugs as an aspect of workplace performance potentially diminishes attention on employee alcohol use. Alcohol is the dominant drug contributing to poor job performance; it also accounts for a third of the worldwide public health burden. Evidence from public roadways--a workplace for many--provides an example of work-related risk exposure and performance lapses. In most developed countries, alcohol is involved in 20-35% of fatal crashes; drugs other than alcohol are less prominently involved in fatalities. Alcohol biomarkers can improve detection by extending the timeframe for estimating problematic exposure levels and thereby provide better information for managers. But what levels and which markers are right for the workplace? In this paper, an established high-sensitivity proxy for alcohol-driving risk proclivity is used: an average eight months of failed blood alcohol concentration (BAC) breath tests from alcohol ignition interlock devices. Higher BAC test fail rates are known to presage higher rates of future impaired-driving convictions (driving under the influence; DUI). Drivers in alcohol interlock programmes log 5-7 daily BAC tests; in 12 months, this yields thousands of samples. Also, higher programme entry levels of alcohol biomarkers predict a higher likelihood of failed interlock BAC tests during subsequent months. This paper summarizes the potential of selected biomarkers for workplace screening. Markers include phosphatidylethanol (PEth), percent carbohydrate deficient transferrin (%CDT), gammaglutamyltransferase (GGT), gamma %CDT (γ%CDT), and ethylglucuronide (EtG) in hair. Clinical cut-off levels and median/mean levels of these markers in abstinent people, the general population, DUI drivers, and rehabilitation clinics are summarized for context.Drug Testing and Analysis 02/2012; 4(2):76-82. DOI:10.1002/dta.384 · 2.82 Impact Factor
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- "ng/mg  Cocaine, morphine, 6-monoacetylmorphine Hair 100 m PDMS HS 125 • C, 25 min GC–MS 2–5 pg/mg Opiate analysis  Cocaine, cocaethylene Hair 100 m PDMS DI pH 8.5, NaCl, 25 min GC–MS 0.02–0.08 ng/mg  Cocaine, cocaethylene Plasma 100 m PDMS DI pH 9, NaCl, RT, 25 min GC–MS 11–19 ng/mL Drug abuse  Cocaine, cocaethylene Urine 100 m PDMS DI pH 8–10, RT, 20 min GC–MS 5 ng/mL Patient  Tramadol Plasma 65 m PDMS/DVB HS NaOH, 100 • C, 30 min GC–MS 0.2 ng/mL Healthy volunteers  Fentanyl Plasma PDMS, own preparation HS pH 12, 85 • C, 30 min GC–MS 0.01 ng/mL Patch treatment  Ethyl glucronide Hair 85 m CAR/PDMS HS 90 • C, 10 min GC–MS–MS 0.6 pg/mg Derivatization  Strychnine Blood 65 m CW/DVB DI Dilution (1:10 H2O), RT, 20 min GC–MS 7 ng/mL Poisoned individuals  -Tetrahydrocannabinol, cannabinol, cannabidiol Hair 100 m PDMS HS + OFD 125 • C, 20 min GC–MS 0.01 ng/mg Derivarized with BSTFA/TMCS   -Tetrahydrocannabinol, cannabinol, cannabidiol Hair 100 m PDMS HS NaOH, Na2CO3, 90 • C, 40 min GC-ITMS-MS 0.007–0.031 ng/mg THC-D3 (internal standard)  "
ABSTRACT: Biomedical analyses of drugs, metabolites, poisons, environmental and occupational pollutants, disease biomarkers and endogenous substances in body fluids and tissues are important in the development of new drugs, therapeutic monitoring, forensic toxicology, patient diagnosis, and biomonitoring of human exposure to hazardous chemicals. In these analyses, sample preparation is essential for isolation of desired components from complex biological matrices and greatly influences their reliable and accurate determination. Solid-phase microextraction (SPME) is an effective sample preparation technique that has enabled miniaturization, automation and high-throughput performance. The use of SPME has reduced assay times, as well as the costs of solvents and disposal. This review focuses on recent advances in novel SPME techniques, including fiber SPME and in-tube SPME, in biomedical analysis. We also summarize the applications of these techniques to pharmacotherapeutic, forensic, and diagnostic studies, and to determinations of environmental and occupational exposure.Journal of pharmaceutical and biomedical analysis 04/2011; 54(5):926-50. DOI:10.1016/j.jpba.2010.12.010 · 2.83 Impact Factor
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ABSTRACT: A method has been devised for analysis of the residual gas content of small tetrodes or pentodes. In contrast to other methods which have been reported, the gas content of the tube being studied is not changed markedly by the analysis; analyses may be made repeatedly as the tube is operated, and moderately low pressures (1 × 10<sup>-10</sup>mm Hg) and small quantities (10<sup>-9</sup>cc mm) can be detected. A 90-degree sector magnetic analyzer with a 3-cm radius of curvature and 30-mil slits (resolution 1:20) is sealed to the tube to be analyzed prior to pumping. The analyzer is made of Corning 0120 glass with a conductive lining. The tube being tested serves as an ion source, avoiding the complications of a second hot filament. The device has been calibrated by comparison with known gases on a vacuum station. This method has been applied to study the gas content of the M1941 experimental pentode intended for applications which require extreme life and reliability. The normal gas pressure in this tube, after trolley pumping and 100 hours aging, is about 1 × 10<sup>-9</sup>mm Hg, predominately He, H 2 , and CO. When no getters are used, the partial pressures of H 2 and CO are higher, perhaps 1 × 10<sup>-8</sup>mm Hg. When titanium-alloy anodes are used in tubes without getters, the partial pressure of hydrogen is much higher, up to 1 × 10<sup>-6</sup>mm Hg. A number of these tubes have been followed for over 10,000 hours. Concurrent studies of the cathode emission have shown it to be markedly influenced by small partial pressures of hydrogen when pure nickel cathode cores are used. Hydrogen is very effective in raising the emission, but the emission falls quickly as the hydrogen pressure is reduced. At least part of the improved cathode performance observed in tubes with titanium anodes must be attributed to the increased hydrogen pressure which accompanies the use of titanium anodes. These data on hydrogen with pure nickel s- - hould not be extrapolated arbitrarily to active cathodes.IRE Transactions on Electron Devices 04/1962; DOI:10.1109/T-ED.1962.14969