Object This study is to develope new urine reference material to enhance analytical ability of laboratories in industrial health by applying this material for proficiency test on analysis of markers of exposure to arsenic.

Method Urine samples of 3 concentration levels including criteria of exposure of arsenic were prepared. In addition to arsenic metal ion, monomethylarsonic acid, dimethylarsinic acid and arsenobetaine was added to make similar condition of real urine sample. Stability test for 30 days at 4 different temperatures (25, 4,–20, −80°C) and homogeneity test were performed for these samples. Analytical method used was graphite-AAS.

Result Prepared samples showed good recovery of total arsenic in the range of 97–103% after 30 days at room temperature. All samples were homogeneous at confidence level of 95%, so they were adequate for application as reference materials for proficiency test program. The urinary arsenic was added as one of the inorganic items of Korean proficiency test for biological monitoring in 2016 with 2 labs proficient for this item.

Conclusion The stability and homogeneity of arsenic in urine reference materials were confirmed. The sample was practically useful for domestic proficiency test program.