Determination of Trace Silicate in Water for Semiconductor Industry by Flow Injection Automatic Analysis
- 海洋环境－已发表论文 
The silicomolybdenum can be extracted by solid phase extraction technique on HLB column. Combining with sequential-injection analysis technique, a novel method for the determination of trace silicate in freshwater has been established. The silicomolybdenum blue was enriched by HLB column, and pure water was used to clean the column, then the silicomolybdenum blue was eluted by NaOH solution and detected by spectrophotometer. The optimized experimental parameters were as follows: the concentration of the eluent was 0.01 mol/L; the extracting and eluting flow rate was 28.0 and 3.5 mL/min, respectively; the reaction temperature was 45 degrees C; the reaction time for both molybdosilicic heteropoly acid and silicomolybdenum blue was 5 min; the volumes of the ammonium molybdate, oxalic acid and ascorbic acid solution were 3.5, 3.5 and 1.75 mL, respectively. The proposed method showed the advantages of high sensitivity and reproducibility, for a water sample containing 9.33 mu g/L Si, the RSD was found to be 1.8% (n = 7). The linear range, with different calibration curves, was 0.47 - 117 mu g/L. The detection limit was 0.18 mu g/L, and the recovery was in the range of 96.8% -105%.