Хромато-масс-спектрометрическое определение примесей в фосфине высокой чистоты с использованием капиллярных адсорбционных хроматографических колонок

Abstract

A possibility of the use of capillary adsorption columns in combination with mass-spectrometric detection was investigated with the aim to determine the content of impurities in high-purity phosphine. The effect of the volume of the main substance on separation and determination of impurities was studied. This effect mostly manifests itself with respect to impurities closely located to the front of phosphine. During the change of pressure of the introduced phosphine from 0.1 to 1 atm. the relative retention time of carbon dioxide decreases by 1-5 %. In case of impurity compounds with the retention factor not more than 0.5 the retention time does not depend on the volume of the introduced phosphine. The effect of displacement of impurities is accompanied by the increase in efficiency of a column. In substances eluting after phosphine, e.g., arsine, at pressure input of a sample more than 0.1 atm. there is almost a 10 times decrease is observed in efficiency of the column. The limits of detection of substances of 5∙10 -8 -1∙10 -5 vol. % were attained. They are the best values among those available in literature and for some impurities they by 2-1000 times lower. The content of 35 impurities was detected using the calibrating dependencies and estimates of sensitivity on the values of the total ionization cross sections of the determined substances. The content of impurities was determined in the samples of purified phosphine and in the fractions extracted from the top and the bottom part of rectification column. It was found that carbon dioxide, arsine and propylene are the mostly hard-to-remove impurities. Keywords: phosphine, impurities, gas chromatography–mass spectrometry, adsorption capillary columns, detection limit, trueness (Russian) DOI: http://dx.doi.org/10.15826/analitika.2013.17.4.011 V.A. Krylov 1,2 . O.Iu. Chernova 1 , A.Iu. Sozin 1 , A.P. Kotkov 1,3 , G.V. Pushkarev 2,3 1 G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences, Russia, Nizhny Novgorod 2 N.I. Lobachevsky Nizhny Novgorod State University, Russia, Nizhny Novgorod 3 FGUP NPP “Saljut”, Russia , Nizhny Novgorod