Perfumes (fragrance substances) are used in the formulation of consumer products to provide pleasure to the user and/or to mask malodours of some other ingredients in the products. Perfumes are also used in aromatherapy. A typical perfume may be composed of 10}300 substances selected from a battery of over 3000 synthetic and natural fragrance materials. It has been shown that approximately 2% o...

Surface water reservoirs and aquifers are exposed to contamination by thousands of micropollutants from industrial, pharmaceutical, agricultural and natural origins. Most developed and developing countries implement a water-quality regulation programme to prevent contamination by such chemicals at illegal concentrations. Traditionally, analytical methods based on gas chromatography-mass spectro...

RECEIVED for review February 21, 1978. Accepted June 19, 1978. NMR spectra since two distinct peaks (6 -3.38, 3.78 ppm) caused by these protons are observed in CDCA vs. only one peak (6 -3.45 ppm) caused by the same protons in UDCA. T h e fingerprint region of the spectrum (6 1-2.5 ppm) and the relative position of the CIS methyl peak with respect to tha t of the doublet caused by the Cpl methy...

The determination of propoxyphene in oral fluid using solid-phase extraction and gas chromatography-mass spectrometry is described for the first time. The method employs collection of oral fluid with the Quantisal device, immunoassay screening of the specimen, confirmation of the positive screened samples after extraction using cation exchange/hydrophobic solid-phase extraction columns, optimiz...

An analytical method was set up suitable for the analysis of microbial metabolomes, consisting of an oximation and silylation derivatization reaction and subsequent analysis by gas chromatography coupled to mass spectrometry. Microbial matrixes contain many compounds that potentially interfere with either the derivatization procedure or analysis, such as high concentrations of salts, complex me...

The occurrence of tetrodotoxin (TTX) in sediment from Lake Suwa, Japan, was confirmed by a tissue culture assay, high-performance liquid chromatography, and gas chromatography-mass spectrometry. Altogether, 17 TTX-producing bacteria belonging to five genera were isolated from Lake Suwa and Pond Inokasira. Our results indicate that TTX and TTX-producing bacteria occur even in freshwater environm...

in previous studies, mebudipine, a dihydropyridine calcium channel blocker, showed a considerable potential to be used in cardiovascular diseases. the aim of the current study was to develop a valid method using reversed-phase high performance liquid chromatography coupled with electrospray ionization mass spectrometry to assay mebudipine in the human plasma. separation was achieved on a zorbax...

The paper summarizes critically the current approaches for the calculation of the limits of detection and quantification. In the context of the description of the method based on the calibration line, the arguments concerning the underlying experimental design, the choice of the appropriate model in the univariate regression, the effects of the dispersion characteristics of the data are deeply ...

Disopyramide is determined in serum by gas chromatography with a nitrogen-selective detector, by liquid chromatography, and by gas chromatography--mass spectrometry. Comparable results are obtained with the three techniques, with a within-run and between-run precision of 5 to 10% (coefficient of variation). Least-squares analysis of data on patients' sera, analyzed first by gas chromatography (...