Study on Extraction of Anionic Surfactant Methylene Blue by Spectrophotometry
Anionic surfactants are essential monitoring items in routine environmental laboratories due to their ad-verse effects on water quality.The most commonly used analytical method,Determination of Anionic Surfactants in Water Quality-Methylene Blue Spectrometric Method(GB/T 7494-1987),requires multiple extractions of the water sample.The extraction effect directly affects the absorbance of the sample and the precision and accuracy of the measurement results.By comparing the results of blank methods and self-controlled samples,it was deter-mined that complete extraction could be achieved under the parameters of oscillation time of 50 seconds and fre-quency of 300 r/min.There was no significant difference in the results between manual extraction and instrument automatic extraction.The instrument automatically extracts blank spiked samples with a recovery rate of 95％to 100％and a relative standard deviation of 1.9％.The accuracy and precision are all qualified.In addition,it was found in the experiment that the slope of the curve drawn by the Metrology Institute was significantly higher than that drawn by the Ministry of Ecology and Environment.It is recommended to use the same source of standard so-lution and self-control sample for the experiment.
anionic surfactantsmethylene blue spectrophotometryextractioncondition optimization
万方数据
维普
