METHOD OF DETERMINING CONCENTRATION OF RARE-EARTH ELEMENTS : LANTHANUM, CERIUM, PRASEODYMIUM, NE

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FIELD : chemistry. SUBSTANCE : invention relates to analytical chemistry and can be used in production air quality control of working area. Method of determining concentration of rare-earth elements : lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, in the air of the working zone by mass spectrometry with inductively coupled plasma involves sampling air of the working zone by drawing the analysed air in volume of 0.1–1.5 m3 through an analytical aerosol filter for 5–15 minutes, fixation of air temperature and atmospheric pressure at the moment of sampling, after sampling air filter is decomposed in the tube-type heater, for this filter is placed in a test tube for the tube heater, adding 4.0 cm3 to it concentrated nitric acid, the mixture is held for 2.5–3.0 hours at temperature of +95 °C, cooled to room temperature, deionised water volume is reduced to 10 cm3, the content is mixed, then 0.5 cm3 prepared samples are introduced into a test tube of an automatic sampler of a mass spectrometer, diluted with 4.45 cm3 deionised water is added to produced mixture 0.05 cm3 solution of internal indium standard in deionised water with mass concentration of 1, 000 mcg/dm3 and in obtained sample by mass spectrometry with inductively coupled plasma, concentration of rare-earth elements is determined : lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium, using a calibration curve and taking into account the reduction of the volume of air sampled for analysis to normal conditions, wherein the helium feed rate in the mass spectrometer is 4.5 ml/min, and the rate of delivery through the mass spectrometer of the prepared sample is 0.4 ml/min. EFFECT : providing high sensitivity, accuracy and rapidness of determining rare-earth elements (REE) in the air of a working area. 1 cl, 9 tbl