Method for determining brodifacoum in workplace air by high-performance liquid chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a method for determining brodifacoum in workplace air by high-performance liquid chromatography (HPLC).</p><p><b>METHODS</b>Brodifacoum in workplace air was collected with a polytetrafluoroethylene filter and desorbed by mixed solution of methanol and dichloromethane (20:80, V:V), and was then separated using an ODS column and determined by an ultraviolet detector; retention time was used for identification, and peak area was used for quantification.</p><p><b>RESULTS</b>The concentration of brodifacoum showed a linear relationship with peak area within 0.2∼10.0 µg/ml; the elution efficiency was 91.6%∼95.1%; the detection limit was 0.08 µg/ml (injection volume: 20 µl eluate); the minimum detectable concentration was 0.000 67 mg/m(3) (calculated by 240 L air sample).</p><p><b>CONCLUSION</b>This HPLC method is convenient and simple for air collection and sample preparation and meets the methodological requirements. Therefore, this method can be used for the determination of brodifacoum in workplace air.</p>

Establishment of occupational exposure limit for warfarin in China / 生物医学与环境科学（英文）

This study aims to establish the occupational exposure limit (OEL) in the air for workplace of warfarin based on the available toxicological studies and field investigations by using questionnaire and air monitoring. The clinical therapeutic dose was used as lowest observed effect level (LOEL), and no observed effect level (NOEL) was achieved by using a safety factor. The highest concentration of warfarin monitored in the worksite of centrifuge washing, drying and packing were 0.029 mg/m3, 0.051 mg/m3 respectively, which did not exceed the OEL 0.1 mg/m3 recommended by NIOSH and ACGIH. Considering its feasibility for enforcement and protection for workers, we recommend OEL 0.1 mg/m3 of warfarin in China.

Determination of brodifacoum in rat plasma by HPLC / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>A determination method of brodifacoum in rat plasma with bromadiolone as an internal standard was developed.</p><p><b>METHODS</b>A volume of 10 microl internal standard (bromadiolone) was added into rat plasma, and then extracted by 0.5 ml of acetonitrile by shaking for 2 min. The residue was dissolved with 200 microl of mobile phase after centrifugation for 10 min, and evaporation to dryness by Nitrogen blowing. A C18 column and PDA detector were used for separating and detecting. The wavelength was 254 nm, the flow rate was 1.0 ml/min, and the injection volume was 20 microl.</p><p><b>RESULTS</b>The liner range was 1.0-20 microg/ml, and the correlation coefficient was 0.9992. The detection limit was 0.3 microg/ml in plasma (S/N=3). The intra-assay and inter-assay coefficients of variation were 1.89%-2.45% and 2.51%-3.61% respectively. The recoveries in plasma at levels of low, middle and high concentrations were (80.8 +/- 3.1)%, (81.8 +/- 2.7)% and (87.9 +/- 3.6)% (n=6), respectively. The accuracies were 84.1%-91.5% and 86.7%-93.2%, respectively.</p><p><b>CONCLUSION</b>This method is simple, fast and accurate for the determination of brodifacoum in rat plasma.</p>