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Objective To establish a method for the determination of thallium and its soluble compounds in workplace air using microporous filter membrane sampling and inductively coupled plasma mass spectrometry (ICP-MS). Methods Thallium and its soluble compounds in workplace air were collected using microporous filter membranes, digested with nitric acid, quantified using lutetium internal standard method, and detected by ICP-MS. Results The linear range of thallium was 0.00 to 600.00 μg/L, with the correlation coefficient of 1.000. The detection limit was 0.08 μg/L, and the lower limit of quantification was 0.26 μg/L. The minimum detection concentration and minimum quantitation concentration of thallium of 75.00 L workplace air were 1.0×10-5 and 3.0×10-5 mg/m3, respectively. The minimum detection concentration and minimum quantitation concentration of thallium of 480.00 L workplace air was 2.0×10-6 and 5.0×10-6 mg/m3, respectively. The recovery rate of spiking was 100.82%-103.44%, and the relative standard deviation within- and between-batches was 1.50%-3.32% and 1.32%-3.11%, respectively. The sample could be stored at room temperature for at least 14 days. Conclusion This method can be used for the detection of thallium and its soluble compounds in workplace air.
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Objective To establish an infrared spectrophotometric method for determination of mineral oil mist in workplace air. Methods The mineral oil mist in workplace air was sampled with glass fiber filter membrane and eluted with carbon tetrachloride. Petroleum-like standard solution of carbon tetrachloride was used as the calibration standard, and quantitative analysis was performed using infrared spectrophotometric oil analyzer. Results The sampling efficiency of the glass fiber filter membrane ranged from 94.8% to 99.2%, and the extraction efficiency ranged from 95.6% to 104.2%. The linear range of mineral oil mist was 1.00-120.00 mg/L, with a correlation coefficient of 0.999 4. The detection limit was 0.52 mg/L, and the quantification limit was 1.74 mg/L. The average recovery rate ranged from 98.8% to 104.1%. The within- and between- run relative standard deviations were 2.2%-6.4% and 2.3%-5.2%, respectively. The samples were stable at room temperature for seven days. This method could be used for air sampling of mineral oil mist in workplaces where mineral oil is used. Conclusion The method is sensitive, accurate, and efficient, which is suitable for determining the concentration of mineral oil mist in workplace air.
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OBJECTIVE: To establish a method for testing lithium and its compounds in workplace air by inductively coupled plasma mass spectrometry(ICP-MS). METHODS: Lithium and its compounds in workplace air were collected by microporous filtration membrane. After elution with nitric acid solution in volume fraction of 1.0%, the samples were determined by ICP-MS. RESULTS: The linearity range of lithium mass concentration was 10.00-500.00 μg/L, and the correlation coefficient was 0.999 8. The detection limit was 0.03 g/L and the lower limit of quantitation was 0.10 μg/L. The minimum detection concentration and the minimum quantitative concentration of lithium were 4.0 and 10.0 ng/m~3 respectively. The recovery rate of standard addition was 96.18%-100.91%.The within-run and the between-run relative standard deviation were 1.17%-2.17% and 0.89%-1.54% respectively. Lithium and its compound samples could be stored at room temperature for at least 28 days. CONCLUSION: The method could be used for detection of lithium and its compounds in workplace air.
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OBJECTIVE: To compare the advantages and disadvantages and application range of three methods for detection of urinary mercury. These methods include alkaline stannous chloride cold atomic absorption spectrometry, acid stannous chloride cold atomic absorption spectrometry and atomic fluorescence spectrometry. METHODS: The detection limits, accuracy and precision in these three methods were compared. RESULTS: The alkaline stannous chloride cold atomic absorption method and acidic stannous chloride cold atomic absorption method had a wide linear range(1.000-10.000 μg/L). The detection limit was high(0.265 and 0.556 μg/L, respectively). The atomic fluorescence spectrometry had the narrowest linear range(0.400-2.000 μg/L) and the lowest detection limit(0.048 μg/L). The average spiked recoveries of the above three methods were 95.93%-101.02%, 92.49%-98.72% and 95.96%-99.57%. The relative standard deviations within and between batches of these three methods were less than 5.00%. The addition recovery of organic mercury by alkaline cold chloride atomic absorption method was 80.91%. The recoveries of inorganic mercury and organic mercury by other methods were close to 100.00%. CONCLUSION: All three methods meet the daily needs of detecting urinary mercury. Among them, alkaline stannous chloride cold atomic absorption method is suitable for promotion in primary laboratories as a preliminary screening method. The atomic fluorescence spectrometry is suitable for the detection of microscale and trace amount of urinary mercury.
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OBJECTIVE: To establish a method for simultaneous detection of 2-methoxyethoxy ethanol( 2-MEE) and2-ethoxyethoxy ethanol( 2-ETE) in workplace air by solvent desorption-gas chromatography. METHODS: The 2-MEE and 2-ETE in workplace air were collected by activated carbon tubes and desorbed with methanol-methylene chloride( 5 ∶ 95,V/V),then separated on DB-FFAP capillary chromatographic column,and finally detected using flame ionization detector.RESULTS: The 2-MEE and 2-ETE showed a good linear range in 2. 12-8 464. 00 and 2. 11-8 428. 00 mg/L respectively and the correlation coefficients was 0. 999 8. The minimum quantification limits were 0. 16 and 0. 20 mg/m~3 respectively( 3 L air sample). The average desorption efficiencies were 99. 33%-103. 72% and 99. 61%-104. 07% respectively. The withinrun relative standard deviations( RSDs) were 3. 68%-4. 73% and 3. 47%-4. 39% respectively,and the between-run RSDs were 4. 72%-6. 99% and 4. 77%-6. 28% respectively. The samples could be stored at room temperature for at least14 days. CONCLUSION: This method is simple,sensitive,precise and suitable for simultaneous detection of 2-MEE and 2-ETE in workplace air.
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OBJECTIVE: To evaluate the technical level and ability of the detection of free silica in dust in occupational health technical service institutions of Guangdong Province through inter-laboratory comparison. METHODS: The interlaboratory detection of free silica in dust in 55,61,58 and 66 occupational health technical service institutions were carried out and compared in 2012-2015. The results were statistically analyzed by four points robust statistical technique,and the relative deviation between the laboratory test results and the Median of them was used as the auxiliary evaluation index of the laboratory's technical ability. RESULTS: The stable coefficient of variation(CV) of samples with free silica content > 20. 00% was less than 5. 00%,and the stable CV of samples with free silica content ≤20. 00% was more than5. 00%. The qualified rate in 2012-2015 were 89. 09%,81. 97%,77. 59% and 81. 82%,respectively. There was no statistical difference(P > 0. 05) in the annual reference between private and non-private institutions compared to the qualified rate in 2012-2015. There was no statistical difference(P > 0. 05) in the qualified rate of the institutions in the Pearl River Delta region and in the non-triangular regions of the Pearl River Delta in 2012-2015. CONCLUSION: Comparison of the detection technology service ability in the detection of free silica in dust should be conducted to improve its technical service quality.