Low concentration anionic surfactant determination steps This method is applicable to surface water and groundwater, or clean effluent from sewage treatment plants. The chloroform used is a 10ml system. Instrument model used: Jinan Shengtai automatic liquid-liquid extractor, model: STC-302B.

Test steps:
1. Transfer 100 ml of the sample to a 250 ml separatory funnel. If the sample concentration is high, dilute the sample to 100 ml.
2. Add 25 ml of methylene blue, mix well, set the extraction instrument to 50 Hz, time 90 s, and let stand for 20 min.
3. Add 10 ml of chloroform, extraction intensity at 25 Hz, extraction time at 90 s, interval of 30 s, 2 times, and let stand to separate the layers.
4. Wipe the inner wall of the separatory funnel with filter paper, plug a small ball of dry cotton wool into the tube, pass the chloroform layer through the dry cotton wool into a 10mm cuvette, and measure the sample absorbance at 652nm using chloroform as a reference.
5. For blank test, only 100 ml of water is used instead of the sample.

The test procedure is

High concentration anionic surfactant determination steps This method is suitable for low concentration surface water and groundwater, as well as domestic sewage, medical wastewater and industrial wastewater. The chloroform used is a 25ml system.
Instrument used: Jinan Shengtai automatic liquid-liquid extractor, model: STC-302B.
Test steps:
1. Transfer 100 ml of the sample to a 250 ml separatory funnel. If the sample concentration is high, dilute the sample to 100 ml.
2. Add 25 ml of methylene blue, mix well, set the extraction instrument to 50 Hz, time 90 s, and let stand for 20 min.
3. Add 25 ml of chloroform, extraction intensity at 25 Hz, extraction time at 90 s, interval of 30 s, 3 times, and let stand to separate the layers.
4. Wipe the inner wall of the separatory funnel with filter paper, plug a small ball of dry cotton wool into the tube, pass the chloroform layer through the dry cotton wool into a 10mm cuvette, and measure the sample absorbance at 652nm using chloroform as a reference.
5. For blank test, only 100 ml of water is used instead of the sample.

The test procedure is

Instrument used: Automatic liquid-liquid extractor, model: STC-302B