Abstract
Sodium silicate and sodium tripolyphosphate in detergents were determined automatically by using Technicon Auto Analyzer. Detergents were fused with alkali carbonates to form soluble silicate and orthophosphate from sodium silicate and tripolyphosphate. Then, the alkali fused sample solution was neutralized and determined colorimetrically.
Silicate is measured at 420nm based on silicomolybdate method, and phosphate is measured at 660nm based on molybdenumblue method. Both compounds were determined using the same sample solution without interference and also determined simultaneously. The range of determination for silicate was from 10 to 100mg/l, and for phosphate from 50 to 300mg/l. Forty samples could be determined within one hour.
