PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 4055946

Nitrogen-sensitive thermionic detection in microcolumn liquid chromatography.

J C Gluckman·M Novotny
View original source ↗Export metadata ↓

Abstract

The dual-flame thermionic detector for microcolumn liquid chromatography has been improved and optimized for nitrogen sensitivity. The total column effluent is concentrically nebulized and aspirated directly into an air-hydrogen diffusion flame, while detection limits of 1.4 X 10(-11) g nitrogen/sec at the maximum of a Gaussian peak are achieved. Detection linearity spans three orders of magnitude. An example of the analysis of underivatized barbiturate standards is provided.

Explore related subjects

BarbituratesChromatography, LiquidIndicators and ReagentsNitrogenTemperatureJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J C Gluckman, M Novotny. 1985-10-04. Nitrogen-sensitive thermionic detection in microcolumn liquid chromatography.. https://doi.org/10.1016/s0021-9673(01)87359-3

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Chiral separation of barbiturates and hydantoins by reversed-phase high-performance liquid chromatography using a 25 or 50 mm short ODS cartridge column via beta-cyclodextrin inclusion complexes.

A high-performance liquid chromatographic method on a 25 or 50 mm short ODS cartridge column has been developed for the resolution of the enantiomers of some optically active barbiturates and hydantoins in human serum. beta-Cyclodextrin was used in the mobile phase. This method also seems to be an easy and effective way to test whether beta-cyclodextrin would be a useful chiral discriminator for a particular racemate.

Barbiturates↗
PubMed1992

[The use of drugs for euthanasia and assisted suicide in family practice].

An exploratory, descriptive, retrospective study was carried out concerning the use of means for euthanasia or assisted suicide, primarily regarding the period 1986-1989. Data were collected via an anonymous written inquiry among a random sample of family physicians in North Holland (n = 521) and family physicians in the rest of the Netherlands (n = 521). The inquiry contained among others questions about the last case they had encountered. In addition, police reports of euthanasia or assisted suicide administered by family physicians in North Holland (n = 263) were analysed. The response to the inquiry was 67%; (non-respondents did not differ from respondents): 388 cases could be analysed. The use of euthanatics by family physicians in North Holland and those in the rest of the Netherlands was identical. More than 40 different euthanatics were used, most of them incidentally. The most frequently used (combination of) means were a benzodiazepine with a neuromuscular relaxant (23%), a barbiturate with a neuromuscular relaxant (20%), barbiturates (15%) and opioids (12%). Most euthanatics were given intravenously (61%, of which 5% by infusion), orally 21%, intramuscularly 12%, rectally 3% and subcutaneously 2%. The quantities applied varied greatly. The average length of time from the start of the procedure till decrease was 3.8 hours (less than or equal to 1 minute-72 hours). In 12% of the cases complications or unintended effects were reported. Comparison of inquiry and police reports showed some differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Barbiturates↗
PubMed1992

Application of Empore C-8 extraction disks for screening urine in systematic toxicological analysis.

Solid-phase extraction (SPE) by means of disposable columns has become a widely accepted technique for sample pretreatment in toxicology, both for directed analyses and for screening analyses. However, the sample capacity in SPE is usually limited to a few millilitres. Therefore, we have investigated to what extent these problems can be overcome by using Empore extraction disks, consisting of chemically modified C-8 reversed-phase silica, embedded in an inert polytetrafluoroethylene (PTFE) matrix. Human urine was selected as the matrix and dexetimide and mepyramine were initially used as test drugs because these drugs were available in tritiated form. Additional drugs investigated included codeine, hexobarbital, imipramine, methamphetamine, and nitrazepam. In these investigations, the sample capacity for untreated urine was at least 25 mL, and analyte quantities up to 250 micrograms could be retained by these filters. Washing with water/methanol mixtures was successful in removing substantial amounts of endogenous interferences, and methanol proved to be an acceptable eluent. Thus, these disks seem to have interesting potential for toxicological analysis in that sample concentration and cleanup can be achieved at the same time.

Barbiturates↗