Use of solid phase extraction for the determination of additives in automotive oils using the GC / MS

Abstract

Currently, the determination of additives in lubricating oils is carried out using such analysis methods as IR spectroscopy, TLC, HPLC-UV, GC, GC-MS. To eliminate the interfering influence of the base oil components, various sample preparation methods are used, which are often not suitable for isolating a wide range of additives, are poorly reproduced, or are completely absent. In this regard, the urgent problem is the development of sample preparation techniques that can effectively isolate various additives for subsequent analysis. This paper presents a methodology for determining additives for the subsequent identification of automotive lubricating oils (MO). The method includes sample preparation by the method of solid phase extraction (SPE) with subsequent analysis by GC / MS. The optimal conditions for obtaining a characteristic and reproducible additives profile were determined: silica gel drying temperature, analyte elution rate, composition of the elution mixture, volumes of washing liquid and eluent. This method of SPE allows to isolate a wide range of additives: sterically hindered phenols, alkyl diphenylamines, dialkyldithiophosphates of zinc, alkyl salicylates, alkyl phenolates and components of extreme pressure additives. Also reduced the number of stages of the procedure SPE was compared with known methods. Keywords : lubricating oils, additives, solid-phase extraction, gas-liquid chromatography / mass spectrometry, GC/MS (Russian) DOI: http://dx.doi.org/10.15826/analitika.2019.23.4.001 R.L. Akhmedov 1 , S.S. Kravtsova 1 , K.A . Dychko 1 , I.V. Ramus’ 2 1 Tomsk State University, Lenin Ave, 36, Tomsk, 634050, Russian Federation 2 EFC DMIA of Russia in Tomsk region, Vershinina st, 17/1, Tomsk, 634041, Russian Federation