Analysis of sodium alkylsulfate in detergent powders
1966 Volume 15 Issue 12 Pages 1364-1368
Details
1966 Volume 15 Issue 12 Pages 1364-1368
The analysis of alkylsulfate (ASNa) in detergent powders involving ASNa and sodium dodecylbenzene sulfonate (ABSNa) as main constituents was studied by means of an infrared spectroscopy (IR) after an extraction with 90% ethanol. Potassium bromide disk method was successfully applied. Quantitative analysis with sulfuric acid hydrolysis was also studied.
ASNa was detected by its characteristic absorption bands at 1085 cm -1and about 1000 cm-1, and the limit of detection was 10%. The amount of ASNa was determined by measuring the extinction quotient [1085 cm-1/(1085 cm-1+1045 cm -1)], but selection of the base line had been very difficult. The recommended procedure among various ways studied was as follows. When the content of ASNa is less than about 40%, the base line is drawn parallel to the 0% line from the point of absorption at 1030 cm-1, and when the content is more than about 40%, the base line is drawn through the points of absorption at 1110 cm-1 and 1030 cm-1. The standard deviations in the quantitative analysis of ASNa were 1.81% and 1.76% for the IR method and the hydrolysis method, respectively.
