GONG Yan1, WEN Sheng2, LI shu-qian1, HU ding-jin1, LIU Jian-tong3, Ao Hong-yi3, Fan Ming-yong1
(1. Institute of Agricultural Quality Standards and Testing Technology, Hubei Academy of Agriculture Sciences, Wuhan 430064, China; 2. Hubei Provincial Centre for Disease Control and Prevention, Wuhan 430079,China; 3. Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072,China)
Abstract: The single affecting factor methods is combined with the orthogonal test to study the interference of arsenic speciation and the main interference factor, and to determine the optimal amount of sodium thiosulfate and the best developing time in the ammonium molybdate spectrophotometric detection of total phosphorus in water. Results showed that the interference effects of arsenic species are: arsenate > arsenite >> dimethylarsinic. When the arsenic concentration is lower than 2.0 mg/L, the developing time is the main influence factor. When the arsenic concentration was in the range of 0.1~5.0 mg/L, the optimal amount of sodium thiosulfate (40 mg/mL) was 0.5 mL and the best developing time was 15 min with the consideration of the practical operation and real sample.
Key words: ammonium molybdate spectrophotometry; water quality; total phosphorus determination; arsenic interference cancellation
E-mail: gongyan1026@qq.com
Analysis and Testing Technology and Instruments, Vol. 17, No. 1, 2011, 36-41.
