BS ISO 21264:2019 pdf free.Surface active agents – Detergents -Determination of alkylphenol ethoxylates.
The sample is weighed into a vial and extracted in methanol using an ultrasonic bath. Subsequently the extract is filtered and analysed using high performance chromatography system with diode array detector (DAD] or fluorescence detector (FLD). Quantification is achieved by external quantification method and using the relationship chromatographic peak through its unique its retention time.7.1 Standard preparation 7.1.1 Prepare 1 000 mg/l stock solutions of each APEOs from standard materials or certified solutions in methanol. 100 mg of the OP,EO (5.2) and NP,EO (5.3) are dissolved in different 100 ml volumetric flasks with methanol and filled up to the mark respectively. Depending on the stock concentrations prepared, the solubility at that concentration will have to be ensured. 7.1.2 Prepare calibration curve for samples of each APEO stock standard solution at required concentrations by adding aliquots of stock solutions to a 100 ml volumetric flask and then diluted with methanol to the desired calibration level. If lower reporting limit is required, lower concentration of
calibration standard shall be prepared to cover the reporting limit. Each calibration curve is prepared using the respective stock solution. The preparation of the Level 5 standard can be accomplished using different volumes and concentrations of stock solutions as is accustomed in the individual laboratory.
The calibration vials shall be used within 24 h to ensure optimum results. Stock calibration standards are routinely replaced every 14 days if not previously discarded for quality control failure. 7.2 Sample preparation The laboratory samples shall be prepared and stored in accordance with ISO 607. The test samples can be in liquid, paste or solid form. Liquefaction and homogenization can be necessary for paste and solid substances. Liquefaction can be accelerated by gentle warming (below 50 °C). Weigh approximately 1,0 g (accurate to 0,1 mg) of the test sample to 50 ml volumetric flasks and make
up to volume with methanol. Put the flask into an ultrasonic water bath and extract at least 30 min. Then filter the extracts through a 0,45 um nylon filter disc for analysis. BS ISO 21264 pdf download.