| [Objective] To establish a rapid detection method regarding the air conditions of workplace and the workers’ urine included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds based on inductively coupled plasma mass spectrometry(ICP-MS) method,then provide a reasonable and effective detection method for hard metal workplace occupational health status evaluation and the studies for hard metal related diseases contact bio-marker.[Methods] The experiment adopts the inductively coupled plasma mass spectrometry(ICP-MS) to determine the tungsten, cobalt, nickel, titanium, manganese, cadmium, lead and its compounds in workplace air and workers urine, selected of the experimental condition, sample pretreatment process, evaluated the performance of the method, thus applied to hard metal work site measurement, specific as follows:(1) Experimental conditions choosing the most optimal instrument working parameters, making experiment of digestion reagents,internal standard element, to decided the best test condition. Micro-porous membrane filter is using microwave digestion method for processing, urine with direct dilution method and microwave digestion method.(2) The method of performance evaluation Making different concentrations of standard series by drawing standard curves. To identify the linear range of the measurement method and the calculation methods of detection limit. The mixture solutions mixed with different concentration of standard solution, calculated thesample of standard addition recovery rate and the accuracy evaluation of the method; By determined the concentration of six standard addition sample, calculated relative standard deviation(RSD), and determined the same concentration of parallel samples to evaluate the precision of the method; At the same time,using the membrane filter and urine freeze-dried metal standard material to verify this method.(3) The application of the method Selected a hard metal enterprise in Shandong province, collected the air samples; Treated the individual sample workers as exposed group, according to the proportion of 1:2, choosing a certain number of exposed workers as control group, collected the urine sample at the end of day shift. Determined the samples with the established method and used SPSS to analyze the data.[Results] 1 ICP-MS determination of linear range and detection limit Drawing the standard curve of air samples during the concentration of 0 ~ 100μg/L, 0 to~500μg/L,the detection limit is 0.024μg/L ~ 0.256μg/L, and then the standard curve of urine samples in the concentration of 0 ~ 20μg/L,the detection limit of direct dilution sampling by ICP-MS is0.011μg/L ~ 0.087μg/L,the detection limit of microwave digestion by ICP-MS is 0.009μg/L ~ 0.079μg/L, each element of correlation coefficient were greater than 0.999. 2.ICP-MS determination of the accuracy and precision The recovery rate of air samples was 95.2% ~ 104.6%,urine diluted sample directly by ICP-MS was 93.0% ~ 103.6%,the microwave digestion by ICP-MS was 92.0% ~ 101.8%. Within-batch precision RSD of the 3 types of samples were 1.41% ~ 3.5%, 1.25%~3.56%,1.23%~3.97%,between-run precision was 1.28%~4.31%, 1.58%~4.67%,1.56%~3.89%. In this experiment based on national level standard membrane lead, cadmium, manganese zinc component to analysis standard material,Freeze-dried urinary chromium standard material, Lyophilized human urine cadmium, the determination results are shown in the table. According to the method every element is within the scope of the standard reference, it was also shows that the established method is accurate and reliable. 3 Application in hard metal related enterprise 3.1 Enterprise workplaces air and urine determination in workersExposed workers are grinding workers, a total of 91 people, divided into the abrasive belt grinding, fine grinding wheel and cloth belt wheel, 17 points are selected, and 25 exposed workers, collecting air samples and urine.The tungsten, cobalt, nickel, titanium, manganese, cadmium, lead and its compounds in the air are in the scope of the occupational exposure limit, not exceed; Cobalt and lead in the urine of exposure group and control group are different(not more than observation object in the diagnosis of lower limit), there were no significant difference in the rest of the urine metal. 3.2 The correlation analysis of metal content in the air and in the urine Compared the air sampling on individual workers of tungsten and cobalt with these inside the urine. Though the cobalt content in the urine was no significant difference in the exposure group and control group,but it has a certain correlation in the air with the urine, r=0.684; However,it has never found the certain correlation of cobalt.[Conclusion] ICP-MS is a trace element determination technology not only high sensitivity, but also without complex sample processing, whereas it makes the whole measurement process, economy rapidly and accurately. ICP-MS determination of membrane and urine of tungsten, cobalt, nickel, titanium, cadmium, manganese, lead and its compounds, such as membrane after microwave digestion, urine after micro-filtration membrane or after microwave digestion, dilute directly with 2% HNO3, using online to join the internal standard is simple,rapid,high sensitivity and precision,and low detection limit, linear range wide,and the characteristics of less disturbance between elements,moreover it is an effective and feasible method. |
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