ABSTRACT
Mass spectral fingerprints of detergents in Austrian, Hungarian, Uruguayan, and Chilean gasolines have been obtained using electrospray ionization mass spectrometry. Polymers or copolymers were observed based on ether motifs (inter-peak spacings of 44, 58 and 72 u) in all samples. Austrian gasoline was found to also contain polymers based on isobutene-amine.
ABSTRACT
Interfacing and evaluation of packed column supercritical fluid chromatography (SFC)-microwave-induced plasma atomic emission detection (AED) is described. Via a flow splitter and an integral restrictor, efficient transfer of solutes from column to detector without band broadening is obtained. Variation of CO2 flow-rate during pressure gradients has little influence on both AED signal and baseline drift while it provides similar sensitivity as in capillary SFC. Continuous introduction of CO2 in the plasma reduces the available range of emission domains; nevertheless the region of detection which is free of CO2 interferences allows selective detection of C1 and Br as reported in this paper. reserved.
Subject(s)
Chromatography, Gas/methods , Electron Probe Microanalysis/methods , Carbon Dioxide/chemistry , Herbicides/analysis , Microwaves , Phenylurea Compounds/analysis , Sensitivity and SpecificityABSTRACT
Pentafluorobenzyl ester derivatives were used to identify zinc dialkyldithiophosphates and diaryldithiophosphates antiwear engine oil additives by GC-electron impact ionization (EI) MS and GC-electron-capture negative ion chemical ionization (ECNCI) MS analysis. GC-EI-MS of the dialkyldithiophosphate-pentafluorobenzyl derivatives afforded characteristic fragment ions corresponding to the cleavage of one and two alkyl radicals. In most cases, information was only obtained on one alkyl chain. Additional and complete information was obtained with retention time indices using synthetic derivatives and with GC-ECNCI-MS analysis. ECNCI afforded characteristic dithiophosphate anions which allowed the determination of the total number of carbon atoms in the alkyl radicals. The diastereoisomer mixtures of 2-hydroxy-sec.-alkyl radicals were completely separated on GC analysis.
