Sir,—MacDonald and Mackenzie (1976) reported an alinear relationship between peak height and halothane concentration when measuring halothane (0.2—4.0%) with a gas chromatograph equipped with a flame ionization detector. Alinearity persisted when the sample loop size was reduced from 2 ml to 0.1 ml, and a linear response was obtained only when the flame ionization detector was replaced with a k...

Gas chromatography-atmospheric-pressure chemical ionization-time-of-flight mass spectrometry (GC-APCI-TOFMS) was compared to GC × GC-electron ionization (EI)-TOFMS, GC-EI-TOFMS, GC-chemical ionization (CI)-quadrupole mass spectrometry (qMS), and GC-EI-qMS in terms of reproducibility, dynamic range, limit of detection, and quantification using a mix of 43 metabolites and 12 stable isotope-labele...

A novel analytical procedure has been developed for the analysis of ultra trace levels of 1,2-dichloroethane (EDC) in air using sample enrichment in combination with micromachined gas chromatography (GC) and differential mobility detection (DMD). When compared to other contemporary GC techniques, such as GC-flame ionization detection, GC-electron capture detection, or GC-electrolytic conductivi...

A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (...

The volatile and polar solvent 1,4-dioxane has recently been reported as a contaminant of ground and surface waters, establishing the need to determine this substance in drinking water. This investigation established that 1,4-dioxane can be determined in water by various techniques including direct aqueous injection (DAI) gas chromatography (GC) and purge and trap GC-mass spectrometry (MS). Pur...

The coupling of gas and liquid chromatography with mass spectrometry is addressed from the historical point of view. This paper discusses the more important coupling interfaces developed for GC/MS and LC/MS, including the moving belt interface, direct liquid introduction interfaces, thermospray and atmospheric pressure ionization interfaces such as atmospheric pressure chemical ionization and e...

AbstractThe oldest method for the managing of the illness is the use of medicinal plants. The use of herbal products as the first choice in self-treatment of minor conditions continues to expand rapidly across Iran. This makes the safety of herbal products an important public health issue.Pesticides are used widely in agriculture to increase the production by controlling the harmful insects and...

Carbonyl compounds (aldehydes and ketones) are suspected to be among the chemical compounds responsible for Sick Building Syndrome and Multiple Chemical Sensitivities. A headspace gas chromatography/mass spectrometry (GC/MS) analysis for these compounds was developed using derivatization of the compounds into volatile derivatives with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBOA). For GC...

The Minamata disease, first identified in Japan the 1950s, is caused by severe methylmercury (MeHg) poisoning. To prevent development of this routine evaluation MeHg levels blood samples crucial. purpose research was to explore use derivatization and capillary gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) for quantitative detection both organic inorganic mercury ...

This study is focused on the effects of nitrogen content in biomass feedstock on the producer gas composition and the flue gas NOx emissions from a pilot-scale gasification and combustion system. Biomass gasification has the potential to produce carbon negative energy by using renewable resources. The greenhouse gases emitted by burning fossil fuels have to be reduced, and biomass gasification ...