Trace Analysis of Phenols in Water by Gas Chromatography

1975 ◽  
Vol 32 (2) ◽  
pp. 292-294 ◽  
Author(s):  
Derek A. J. Murray
Keyword(s):  
Gas Chromatography ◽  
Lower Limit ◽  
Water Samples ◽  
Trace Analysis ◽  
Organic Material ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Low Concentrations ◽  
Trimethylsilyl Derivatives ◽  
Derivatives Of

A method for analysis of low concentrations of phenols, cresols, and xylenols in water samples was developed. O-xylene was added to the sample as an internal standard and the sample was extracted once with chloroform to remove a portion of the total organic material present. The trimethylsilyl derivatives of the phenols were formed and analysis completed by gas chromatography. The method was rapid and required a minimum of sample manipulation. The lower limit of detection was 0.100 mg/liter for phenol, 0.025 mg/liter for cresols, and 0.050 mg/liter for xylenols.

Electron-capture gas chromatography as a sensitive method for measuring subnanogram amounts of cholesterol in saliva and urine

1990 ◽  
Vol 36 (3) ◽  
pp. 519-521 ◽  
Author(s):  
H A Schwertner ◽  
E R Johnson ◽  
T E Lane
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Cholesterol Concentration ◽  
Tissue Samples ◽  
Flame Ionization ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Sensitive Method

Abstract This is a sensitive method, suitable for measuring subanogram amounts of cholesterol. Cholesterol and the internal standard, epicoprostanol (5-beta-cholestan-3-alpha-ol), are derivatized with pentafluorobenzoyl chloride and detected by electron-capture gas chromatography. The pentafluorobenzoyl esters of cholesterol and the internal standard are easily formed and possess excellent chromatographic and electron-capturing properties. The lower limit of detection of the method, approximately 100 pg injected, is about 500-fold as sensitive as chromatographic methods involving flame-ionization detection. Within-day and between-day coefficients of variation were 4.2% and 8.2%, respectively, for determinations of a urinary cholesterol concentration of 570 micrograms/L (1.47 mumol/L). Such sensitivity permits analysis for cholesterol in (e.g.) physiological fluids, tissue samples, and cell cultures that contain very low concentrations of cholesterol.

Determination of Nitrilotriacetic Acid in Inland Waters by Gas Chromatography of the Trimethyl Ester

1971 ◽  
Vol 28 (7) ◽  
pp. 1043-1047 ◽  
Author(s):  
D. Murray ◽  
D. Povoledo
Keyword(s):  
Gas Chromatography ◽  
Natural Waters ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Nitrilotriacetic Acid ◽  
Inland Waters ◽  
Gas Chromatograph ◽  
Methyl Heptadecanoate ◽  
Low Concentrations

A method for the analysis of low concentrations of nitrilotriacetic acid (NTA) in natural waters was developed. The NTA was converted to the trimethyl ester and determined quantitatively by gas chromatography using methyl heptadecanoate as an internal standard. The lower limit of detection was 25 μg/liter of NTA. The identity of the ester was confirmed using a mass spectrometer–gas chromatograph combination.

scholarly journals Gas-Chromatographic Determination of the Trimethylsilyl Derivatives of Polyhydric Alcohol Humectants in Tobacco and in Tobacco Smoke

1971 ◽  
Vol 6 (2) ◽  
Author(s):  
N. Carugno ◽  
S. Rossi ◽  
G. Lionetti
Keyword(s):  
Gas Chromatography ◽  
Mass Spectra ◽  
Triethylene Glycol ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Trimethylsilyl Derivatives ◽  
Gas Chromatographic Method ◽  
Derivatives Of ◽  
Quantitative Procedure

AbstractA qualitative and quantitative procedure has been developed for the determination of humectants in manufactured tobacco by gas-chromatographic method with a flame ionization detector. It consists of extraction with methanol, concentration of the extract and treatment with Tri-Sil reagents. The operating gas-chromatographic conditions are set forth. Samples of tobacco containing glycerine, propylene glycol, diethylene glycol, triethylene glycol, 1-3 butylene glycol and sorbitol have been analysed with recoveries, for the first five ones, in the range of 95-104 %. In order to verify that each chromatographic peak corresponded to the relative glycol, with no interference by other silylated compounds, the mass spectra were obtained through the combination of gas-chromatography with mass spectrometry. The results achieved confirm, as far as tobacco is concerned, that the procedure is accurate and precise. The same method for the determination of humectants was extended to cigarette smoke. Even though this involves morecomplicated problems, as compared to tobacco, because of the presence of silylated compounds, it was found that, for certain glycols, the gas-chromatography of the trimethyl derivatives can be also used as a method of analysis. The mass spectra of some polyhydric alcohols are shown

scholarly journals Determination of Tianeptine in Tablets by High-Performance Liquid Chromatography with Fluorescence Detection

2007 ◽  
Vol 90 (3) ◽  
pp. 720-724
Author(s):  
Sevgi Tatar Ulu
Keyword(s):  
Lower Limit ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Linear Calibration ◽  
Fluorescence Detector ◽  
Relative Standard ◽  
Validation Parameters ◽  
Limit Of Quantitation

Abstract A sensitive and selective high-performance liquid chromatographic method has been developed for the determination of tianeptine (Tia) in tablets. The method is based on derivatization of Tia with 4-chloro-7-nitrobenzofurazan (NBD-Cl). A mobile phase consisting of acetonitrile10 mM orthophosphoric acid (pH 2.5; 77 + 23) was used at a flow rate of 1 mL/min on a C18 column. The Tia-NBD derivative was monitored using a fluorescence detector, with emission set at 520 nm and excitation at 458 nm. Gabapentin was selected as an internal standard. Linear calibration graphs were obtained in the concentration range of 45300 ng/mL. The lower limit of detection (LOD) was 10 ng/mL at a signal-to-noise ratio of 4. The lower limit of quantitation (LOQ) was 45 ng/mL. The relative standard values for intra- and interday precision were <0.46 and <0.57%, respectively. The recovery of the drug samples ranged between 98.89 and 99.85%. No chromatographic interference from the tablet excipients was found. The proposed method was validated in terms of precision, robustness, recovery, LOD, and LOQ. All the validation parameters were within the acceptance range. The proposed method was applied for the determination of Tia in commercially available tablets. The results were compared with those obtained by an ultraviolet spectrophotometric method using t- and F-tests.

Further studies on the differentiation of Clostridium sordellii from Clostridium bifermentans by gas chromatography

1970 ◽  
Vol 16 (11) ◽  
pp. 1071-1078 ◽  
Author(s):  
John B. Brooks ◽  
V. R. Dowell ◽  
D. C. Farshy ◽  
A. Y. Armfield
Keyword(s):  
Gas Chromatography ◽  
The Other ◽  
Gas Liquid Chromatography ◽  
Carbohydrate Composition ◽  
Whole Cells ◽  
Cultural Medium ◽  
Urease Production ◽  
Clostridium Bifermentans ◽  
Trimethylsilyl Derivatives ◽  
Derivatives Of

Amines produced by 31 strains of the Clostridium bifermentans and C. sordellii groups were compared by examining trifluoroaceticanhydride derivatives of basic chloroform extracts from spent cultural medium by gas–liquid chromatography (g.l.c.). All of the urease-positive strains (16) exhibited an amine profile consistent with that of C. sordellii. On the other hand, 12 of 15 urease-negative strains produced amine g.l.c. patterns like that of C. bifermentans, and three strains produced amine patterns identical with that of C. sordellii. The carbohydrate composition of some of the strains was determined by g.l.c. of trimethylsilyl derivatives of acid-digested formamide extracts of whole cells. Two of the three urease-negative strains with amine profiles like C. sordellii had a carbohydrate composition similar to that of C. sordellii, and the other strain had a carbohydrate profile more like that of C. bifermentans. One known strain of C. bifermentans had a carbohydrate profile with characteristics of both C. bifermentans and C. sordellii. The results of this study point out the variability of urease production by C. sordellii and the value of gas chromatography in differentiating this organism from C. bifermentans.

scholarly journals Gas Chromatography of Trifluoroacetyl Derivatives of Alditols and Trimethylsilyl Derivatives of Aldonolactones

1968 ◽  
Vol 16 (7) ◽  
pp. 1383-1387 ◽  
Author(s):  
MICHIO MATSUI ◽  
MASASHI OKADA ◽  
TOSHIO IMANARI ◽  
ZENZO TAMURA
Keyword(s):  
Gas Chromatography ◽  
Trimethylsilyl Derivatives ◽  
Derivatives Of

Preparation of trimethylsilyl derivatives of ribonucleosides for gas chromatography

1985 ◽  
Vol 348 ◽  
pp. 280-285 ◽  
Author(s):  
E. Csató ◽  
P. Keresztes ◽  
L.D. Szabó ◽  
D. Knausz
Keyword(s):  
Gas Chromatography ◽  
Trimethylsilyl Derivatives ◽  
Derivatives Of
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