PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 3967361

Two automated methods for measuring plasma thiocyanate compared.

C J Vesey·C J Kirk
View original source ↗Export metadata ↓

Abstract

In an interlaboratory comparison of two continuous-flow analytical procedures for measuring thiocyanate, we used ferric nitrate (y) and p-phenylenediamine/pyridine (x) as colorimetric reagents to measure its concentrations in plasma of 100 consecutive patients attending a peripheral vascular disease clinic. The results correlated well (r = 0.987, p less than 0.001; y = 0.938x + 1.2 mumol/L). However, there were small, systematic, positive differences between the phenylenediamine values and the corresponding ferric nitrate values (paired t = 5.4, p less than 0.001). These differences were linearly related to the means of the pairs of results (r = 0.42, p less than 0.001; y = 0.0739x - 2). Nevertheless, when we used previously determined cutoff points the two sets of SCN concentrations concurred completely in classifying the 100 patients as smokers or nonsmokers. On the basis of self-classification by 71 of these subjects, the measurement techniques had a sensitivity of 91% and a specificity of 75%; when five patients claiming to be nonsmokers but found to have abnormally high values for carboxyhemoglobin (2.7 - 6.9%) were reclassified as smokers, specificity increased to 89%.

Explore related subjects

AutoanalysisCarboxyhemoglobinChemical PhenomenaChemistryColorimetryFerric CompoundsHumansIndicators and ReagentsNitratesPhenylenediaminesQuality ControlSmokingThiocyanatesComparative StudyJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C J Vesey, C J Kirk. 1985. Two automated methods for measuring plasma thiocyanate compared.. https://pubmed.ncbi.nlm.nih.gov/3967361/

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

KEEP EXPLORING

Related citations

PubMed1996

Application of capillary electrophoresis to the simultaneous screening and quantitation of benzodiazepines.

Capillary electrophoresis (CE) is an attractive approach for the analysis of drugs in body fluids. We made a simultaneous analysis of nitrazepam, diazepam, estazolam, bromazepam, triazolam and flurazepam using CE with on-column detection at 200 nm. We obtained the best electropherograms under a condition of 5 mM phosphate-borate (pH 8.5) containing 50 mM SDS and 15% methanol. We examined the effect of the sample solvent matrix on the electropherograms obtained, indicating that increasing the methanol content in the sample solvent or the injection volume above a certain threshold limit decreased the resolution. We then focused on application of the CE to the analysis of the drugs in spiked serum, being appropriate for an analysis within 25 min. Linearity, the detection limit, accuracy and reproducibility were established using this method. The calibration curve was linear up to 1 mg/l of serum concentration. The lower limit of detection was 5 pg per injection and 0.025 mg/l of the serum concentration for all the compounds except for flurazepam, for which they were 40 pg/injection and 0.2 mg/l. The detection limits obtained allowed toxicological and pharmacological determinations for nitrazepam, diazepam, estazolam and bromazepam, but not for triazolam and flurazepam. Only toxic blood levels for the latter two benzodiazepines could be quantified by this method. We concluded that the CE could at least be applicable to simultaneous screening for toxic levels of benzodiazepines. We suggest that this technique may offer criminal toxicologists a rapid, simple and adaptable approach for the estimation of many other drugs in body fluids.

Autoanalysis↗
PubMed1996

Electrophoretically uniform fluorescent dyes for automated DNA sequencing.

A class of dyes, BODIPY fluorophores, has been identified for automated DNA sequencing that has improved spectral characteristics compared with conventional fluorescein and rhodamine dyes. Single and double BODIPY dye primers were characterized in commercially available DNA sequencers and showed uniform electrophoretic mobilities and high fluorescence intensities. The improved physical properties of BODIPY dye primers were demonstrated by direct base-calling from the unprocessed fluorescent signals and improved heterozygote analyses of mixed-base populations. The high sensitivity of BODIPY dye primers requires at least 33 percent less reagent consumed per reaction than conventional dye primers, which should affect the costs of large genome-sequencing efforts.

Autoanalysis↗
PubMed1996

"Doublex" fluorescent DNA sequencing: two independent sequences obtained simultaneously in one reaction with internal labeling and unlabeled primers.

The novel "doublex" DNA sequencing technique that makes it possible to obtain simultaneously two independent sequences from one sequencing reaction with the use of unlabeled primers and internal labeling is described. The different sequencing products are labeled in parallel with fluorescein-15-dATP and Texas red-5-dCTP present in the same tube. The characteristics of T7 DNA polymerase are exploited to ensure that only either of the labeled dNTPs is incorporated into the corresponding sequencing products. Specificity of labeling is ensured by the selection of primers. One of the unlabeled primers is chosen to be followed by an "A," the other by a "C" to be incorporated immediately downstream from the primer binding site. The doublex sequencing technique is applicable to the simultaneous sequencing of either the same DNA template/strand or a mixture of different templates. Combinations of unlabeled and labeled primers in the same sequencing reaction are also possible. The two sequences can be determined in parallel and on-line in the same lanes of a gel with a novel automated DNA sequencer, which was previously described for use with labeled primers.

Autoanalysis↗