ABSTRACT
OBJECTIVE: To develop proficiency testing samples of chloroform and carbon tetrachloride in activated carbon tubes and analyze their application in inter-laboratory comparison tests in occupational health technical service organizations. METHODS: Three types of mass concentration proficiency testing samples of chloroform and carbon tetrachloride in activated carbon tubes were developed. Their homogeneity and stability were evaluated and the values were determined. The qualified samples were used for inter-laboratory comparison test in occupational health technical service organizations in the country. RESULTS: The prepared chloroform and carbon tetrachloride activated carbon tubes demonstrated good sample homogeneity. There was no significant difference in the measured values of the samples stored at room temperature for one year and the values measured on the day of preparation( P > 0. 05),and the stability was good.Among the 197 institutions participated in the inter-laboratory comparison test of chloroform,the satisfactory result accounted for 86. 29%( 170/197),the problematic results 7. 11%( 14/197),and the unsatisfactory results 6. 60%( 13/197). Among the 195 agencies that participated in the inter-laboratory comparison test of carbon tetrachloride,the satisfactory results accounted for 89. 74%( 175/195),the problematic results 3. 59%( 7/195),and the unsatisfactory results 6. 67%( 13/195). CONCLUSION: The homogenous and stable proficiency testing samples were successfully produced and can be used for inter-laboratory comparison test in occupational health technical service organizations.