Determination of thallium and its soluble compounds in workplace air by inductively coupled plasma mass spectrometry / 中国职业医学

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.

IImprovement of pretreatment method for detection of lead, manganese and their inorganic compounds in the air of workplace by flame atomic absorption spectrometry / 中国职业医学

OBJECTIVE: To improve the pretreatment method for the detection of lead, manganese and their inorganic compounds in workplace air samples by flame atomic absorption spectrometry. METHODS: In this method, 20.0 mL of 1.0-2.0 mol/L nitric acid solution was used as the digestion solution to digest the microporous membrane sample at 140-160 ℃ to a volume of 0.5-1.0 mL. Samples were cooled and fixed to 10 mL and detected by flame atomic absorption spectrometry method. RESULTS: The lead detection had a good linear relationship in the range of 0.10-3.00 mg/L. The correlation coefficient was 0.999 5, the detection limit and the lower limit of quantification were 0.03 and 0.10 mg/L respectively(calculated by 3 and 10 times of standard deviation respectively). The minimum detection concentration was 0.004 mg/m~3, and the minimum quantitative concentration was 0.010 mg/m~3(collected by 75 L air calculation). The manganese detection had a good linear relationship in the range of 0.05-3.00 mg/L mass concentration. The correlation coefficient was 0.999 8, the detection limit and the lower limit of quantification were 0.015 and 0.05 mg/L respectively(calculated by 3 and 10 times of standard deviation respectively), the minimum detection concentration was 0.002 mg/m~3, and the minimum quantitative concentration was 0.007 mg/m~3(based on collection 75 L air calculation). The recovery rate of standard addition was 97.8%-99.6%, and the relative standard deviation within and between run were 0.4%-2.0% and 0.4%-1.7% respectively. CONCLUSION: The method is simple, the reagent consumption is small, the digestion temperature is low, the precision and accuracy are high. This method is suitable for widespread use.

Determination of lithium and its compounds in workplace air by inductively coupled plasma mass spectrometry / 中国职业医学

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.

Preliminary development and manufacturing of radioactive sewage purification device / 中国职业医学

OBJECTIVE: To develop a radioactive sewage purification device that can effectively filter the nuclides in low-level nuclide-contaminated wastewater. METHODS: The radioactive sewage purification device was composed of lifting pump, stack filter, multi-medium filter, security filter, tubular ultrafiltration membrane, high-pressure pump and reverse osmotic membrane. The combined process of adsorption-ultrafiltration-reverse osmosis was used to separate radioactive elements from wastewater by reverse osmosis membrane separation system. Through two-stage multi-medium filter circulation system circulation treatment, radioactive sewage was purified. The flow rate of water treatment is 20 L/min. The filtration efficiency and purification efficiency of the device were tested by filtration experiments on elements containing radionuclide and purification experiments on radionuclide.RESULTS: The filtration efficiency on iodine, potassium, strontium and cesium, that are the common elements in radioactive sewage samples were 97.88%, 98.38%, 99.99% and 99.80%, respectively. The single purification efficiency of radionuclide ~(40)K in low-level radioactive sewage was over 90.00%. CONCLUSION: The device has high filtering efficiency for common elements such as iodine, potassium, strontium and cesium in sewage and high removal rate of radioactive activity for sewage containing ~(40)K. It can be further optimized and transformed into a suitable radioactive sewage water purifier.

Detecting sulfur dioxide in workplace air by ion chromatography coupled with solid adsorption tube sampling / 中国职业医学

OBJECTIVE: To establish a detecting method for sulfur dioxide in workplace air by molecular sieve solid adsorption tube sampling and ion chromatography. METHODS: Air samples were collected by molecular sieve solid adsorption tubes,desorbed by distilled water,oxidized by hydrogen peroxide in weak base system,separated by anion exchange chromatography and detected by conductivity detector. RESULTS: The good linearity range of sulfur dioxide was0. 10-16. 00 mg/L,and the correlation coefficient was 0. 999 8. The detection limit was 0. 02 mg/L,the minimum detectable concentration was 0. 01 mg/m3. The average desorption efficiency was 96. 53%-99. 35%. The within-run and between-run relative standard deviations were 1. 73%-3. 65% and 1. 80%-4. 46% respectively. The samples could be stored at room temperature for at least 14 days. CONCLUSION: This method is suitable for detecting sulfur dioxide in workplace air.