Determination of thallium with X-ray-fluorescence analysis

4 Determination of thallium with X-ray-fluorescence analysis Concentration 

Evaporate 1 to 20 litres of the water sample to dry matter, pick up with hydrochloric acid and precipitate the thallium as sulphide together with the iron sulphide which serves as carrier. Collect the preparation on a membrane filter and analyze spectrometrically with X-ray fluorescence. 

Draw up, a calibration curve by preparing solutions containing between 10 pg Tl/1 and 1000 pg Tl/1. Use the standard addition method for the analysis, topping up the water samples with the known quantities of thallium added for use as an internal standard and subjecting them to the same analytical procedure (see also Chapter 2). 

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