T/QAS 006-2019 Brine Determination of Potassium, Sodium, Calcium, and Magnesium by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Scope

Main Technical Content: After pretreatment, the samples are measured by an inductively coupled plasma spectrometer. The solution to be tested is introduced into a high-temperature plasma torch, where the elements to be detected are excited into ions and atoms. The emission spectra intensity of these elements is measured at specified wavelengths. The intensity of the characteristic spectra is linearly related to the concentration of the elements in the sample, allowing quantitative analysis. 4 Reagents and Materials Unless otherwise specified, all reagents used in the analysis are of ultra-high purity grade and comply with the requirements of GB/T 6682 for analytical laboratories. a) Nitric acid: ρ(HNO3) = 1.42 g/mL; b) Hydrochloric acid: ρ(HCl) = 1.19 g/mL; c) Potassium standard solution (1000μg/mL): commercially available; d) Sodium standard solution (1000μg/mL): commercially available; e) Calcium standard solution (1000μg/mL): commercially available; f) Magnesium standard solution (1000μg/mL): commercially available; g) High-purity argon gas: argon content ≥ 99.999%. 5 Instruments and Equipment The main instruments and conditions involved in the experiment are as follows (see Appendix A for unmentioned items). a) Inductively coupled plasma emission spectrometer; b) Analytical balance (sensitivity 0.1 mg). 6 Samples The samples are stored in sealed plastic buckets. 7 Analysis Steps 7.1 Sample Pretreatment After appropriate dilution, transfer 25 mL of the sample to a 250 mL volumetric flask, add 5 mL of hydrochloric acid (b), shake well, then add 5 mL of nitric acid (a) to make up to 250 mL (in a dried and weighed volumetric flask), shake well, and use for testing K+, Na+, Ca2+, and Mg2+. 7.2 Preparation of Standard Solutions Accurately transfer 100 mL of the standard solution of the elements to be tested (c, d, e, f) to a 1000 mL volumetric flask, dilute to the mark with water, and the mass concentration of K+, Na+, Ca2

Development Information

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