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Thornleigh, Austria

Hu J.,Chemical Analysis Branch | O'Donnell G.E.,Chemical Analysis Branch | Milosavljevic A.,WorkSafe WA | North S.,WorkSafe WA
Journal of Health, Safety and Environment | Year: 2014

Isocyanates are extensively used in industry particularly in two-pack spray paints, polyurethane and adhesives. They are highly reactive chemicals and can cause respiratory sensitisation and asthma. Usually the measurement of occupational exposure to isocyanates is performed in workplace air. However, more recently, isocyanate-derived amines in a worker's urine have been used to assess exposure. This study presents a highly sensitive and specific Ultra-high Performance Liquid Chromatography-Tandem Mass Spectrometry method for the determination of the isocyanate-derived amines. The method has been fully validated and has a low limit of quantitation of 0.5 μmol isocyanate-derived diamine/mol creatinine. The method was applied to urine samples collected from workers who worked in car smash repair garages and were exposed to hexamethylene diisocyanate. The results indicate that the biological monitoring method gives a more sensitive assessment than the established air monitoring method. The study emphasizes the need to improve control measures in the workplace and to provide training for workers in motor vehicle repair shops. © CCH. Source


Hu J.,Chemical Analysis Branch | Hurst J.A.,Chemical Analysis Branch | O'Donnell G.E.,Chemical Analysis Branch
Journal of Analytical Toxicology | Year: 2012

An analytical method using a liquid chromatograph combined with a simple online column switching sample pre-treatment system was developed for the determination of 1-hydroxypyrene (1-HP) in urine. This compound is the metabolite of pyrene and is used to assess the exposure of workers to polycyclic aromatic hydrocarbons (PAHs). After enzymatic hydrolysis, a urine sample was directly injected into a high-performance liquid chromatograph (HPLC) where it automatically underwent a sample cleanup using a column switching device. The procedure is simpler than previous methods because it uses only one switching valve, one extraction column and one HPLC pump. The analyte was retained on a short extraction column and after interferences were eluted to waste, was subsequently switched onto the analytical column. This allowed a short analysis time of 15 min. The calibration graph was found to be linear within the concentration range of 0.5 to 20 mg/L with a coefficient of determination exceeding r2=5 0.99. Recoveries were found to be greater than 96% in the range 1 to 10 mg/L with intermediate precision of 2.5 to 5.8% relative standard deviation. This online method was verified by a comparison with an existing manual method by the analysis of 81 urine samples from workers exposed to PAHs and showed that the test results from both methods were in agreement with a probability obtained from the paired Student's t-test of P > 0.76. The proposed online method was found to be simple, fast and suited to routine analyses of 1-HP in urine for the assessment of occupational exposure to PAHs. © The Author [2012]. Published by Oxford University Press. All rights reserved. Source


Hurst J.A.,Chemical Analysis Branch | Volpato J.A.,Chemical Analysis Branch | O'Donnell G.E.,Chemical Analysis Branch
Spectroscopy Europe | Year: 2011

Real welding fume samples obtained from inter-laboratory proficiency operated by the Health and Safety Laboratory (HSL) in the UK were analyzed directly by a PANalytical 2.4 KW wavelength dispersive XRF spectrometer with rhodium tube. Average recoveries, standard deviations (SD), and relative standard deviations (RSD), were computed. The analysis shows that the analytical method calibration only needs to be performed once, with calibrations remaining valid for much time, provided monitor drift correction is performed and check samples run. Results have shown that problems may exist with fundamental parameter methods where assumptions may need to be made about the oxidation state of the specimen analyzed, whether to normalize results or not and assumptions made about the nature of the matrix when all elements cannot be determined. Source


Hu J.,Chemical Analysis Branch | Tan Z.,Chemical Analysis Branch | Mazereeuw M.,Chemical Analysis Branch | O'Donnell G.E.,Chemical Analysis Branch
Journal of Health, Safety and Environment | Year: 2014

The exposure to carbon disulfide in an analytical laboratory was assessed by using both air and biological monitoring techniques. The urinary metabolite of carbon disulfide, 2-thiothiazolidine-4-carboxylic acid, was used as the biomarker of the exposure. Low-level test results were found in both the air monitoring samples and the biological monitoring samples. The results indicate that no worker exceeded the American Conference of Governmental Industrial Hygienist biological exposure index of 0.5 mg TTCA/g creatinine (350 μmol/mol creatinine) in urine or the air concentration specified for the threshold limit value of 1 ppm. However, a very low exposure was determined by monitoring the pre-shift and post-shift urine samples of individual workers. This approach proved to be a powerful technique for monitoring low-level exposure. © CCH. Source

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