Gas-Liquid Chromatographic Determination of Total Inorganic Iodine in Milk

1977 ◽  
Vol 60 (6) ◽  
pp. 1307-1309 ◽  
Author(s):  
Hendrik J Bakker
Keyword(s):  
Liquid Chromatography ◽  
Iodine Content ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Gas Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Inorganic Iodine ◽  
Liquid Chromatographic

Abstract Total inorganic iodine in milk is determined by conversion to iodobutanone, which is quantitated by gas-liquid chromatography and electron capture detection. As little as 10 μg/L can be determined. The thyroid-active iodine content of milk can be determined rapidly with a relative standard deviation of 1.9%. Average recoveries for added iodide and iodine were 95.5 and 94.6%, respectively.

Gas-Liquid Chromatographic Determination of Kepone Residues in Finfish, Shellfish, and Crustaceans

1978 ◽  
Vol 61 (4) ◽  
pp. 877-883
Author(s):  
Richard A Carver ◽  
Arnold P Borsetti ◽  
Laverne R Kamps
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Petroleum Ether ◽  
Ethyl Ether ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Finfish, shellfish, and crustacean samples are extracted with isopropanol and benzene; the extract is filtered and then concentrated. The extract, dissolved in hexane, is treated with oleum and extracted with aqueous alkali. The aqueous phase is acidified and extracted with petroleum ether-ethyl ether (1+1). The Kepone residue is determined by electron capture gas-liquid chromatography (GLC). Recoveries obtained by 8 laboratories from 15 species of finfish fortified at 0.02-0.23 ppm ranged from 37 to 107% with a mean ± relative standard deviation of 79.4±14.5%. For oysters fortified at 0.01- 0.10 ppm, recoveries range from 63 to 129% with a mean of 78.2 ±20.8%. For crustaceans fortified at 0.05—0.26 ppm, recoveries ranged from 52 to 110% with a mean of 78.8±16.4%. The approximate limits of quantitation for finfish and for shellfish and crustaceans are 0.02 and 0.05 ppm, respectively, under the GLC conditions used in this study.

Simultaneous Gas-Liquid Chromatographic Determination of Four Sulfonamides in Feeds

1971 ◽  
Vol 54 (6) ◽  
pp. 1277-1282 ◽  
Author(s):  
Robert J Daun
Keyword(s):  
Liquid Chromatography ◽  
Electron Capture ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A procedure is described for the gas-liquid chromatographic determination of sulfathiazole, sulfamerazine, sulfamethazine, and sulfaquinoxaline in finished feeds at levels from 0.002 to 0.05%. The procedure utilizes a double derivatization technique to modify the sulfonamides so that they can be determined by gas-liquid chromatography with electron capture detection. The conditions for extraction, derivatization, and gas-liquid chromatography are given, along with recovery data.

Gas-Liquid Chromatographic Determination of Sodium Fluoroacetate (Compound 1080)

1980 ◽  
Vol 63 (1) ◽  
pp. 49-55
Author(s):  
Iwao Okuno ◽  
Dennis L Meeker
Keyword(s):  
Liquid Chromatography ◽  
Tissue Sample ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Tissue Samples ◽  
Fluoroacetic Acid ◽  
Pentafluorobenzyl Bromide ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract An analytical method is described for the determination of Compound 1080 (sodium fluoroacetate) residues in 1–10 g tissue. Sample extracts of tissues are cleaned up with silica gel, and Compound 1080 (as fluoroacetic acid) is separated by a micro-distillation procedure. The fluoroacetic acid in the distillate is derivatized with pentafluorobenzyl bromide to form pentafluorobenzyl fluoroacetate which is measured by electron capture gas-liquid chromatography. Recoveries of sodium fluoroacetate from fortified tissue samples averaged about 25%. Despite the limited recoveries, results were quite reproducible, and levels as low at 2 ppm were determined in fortified 1 g samples, and 0.2 ppm in 10 g samples. The method is relatively simple and has been used routinely in our laboratory for the analysis of various types of samples such as grain, and tissues from birds, rodents, and larger animals.

Gas-Liquid Chromatographic Determination of Maleic Hydrazide in Tobacco and Tobacco Smoke

1979 ◽  
Vol 62 (1) ◽  
pp. 171-175 ◽  
Author(s):  
Alfred F Haeberer ◽  
Orestes T Chortyk
Keyword(s):  
Liquid Chromatography ◽  
Tobacco Smoke ◽  
Plant Growth Regulator ◽  
Maleic Hydrazide ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Trimethylsilyl Derivative ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is presented for the determination of the plant growth regulator maleic hydrazide (MH; l,2-dihydro-3,6-pyridazinedione) in tobacco and tobacco smoke. Residues are converted to the bis(trimethylsilyl) derivative before analysis by gas-liquid chromatography. The method has been applied to cigarettes and condensed smoke and has been used to determine the per cent transfer of MH into cigarette smoke. Free MH residues could be determined directly on the tobacco samples, whereas total MH values were obtainable only after acid hydrolysis. In spite of large MH residues in tobacco, only 0.2% of the MH was transferred into smoke.

Gas-Liquid Chromatographic Determination of Choline in Low and High Potency Multiple Vitamin Tablets and Liver Preparations

1974 ◽  
Vol 57 (2) ◽  
pp. 341-342
Author(s):  
Caesar B Garavelli
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
High Potency ◽  
Average Recovery ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A procedure is described for the quantitative determination of 0.020—6.0 mg choline in low and high potency reference multiple vitamin tablets and standard liver preparations. The trimethylamine quantitatively produced in a sealed tube by treatment with aqueous 5 0% alkali is simultaneously extracted with 0.200—0.500 ml of an isobutanol-ethanol (1+1) mixture and determined by gas-liquid chromatography. An average recovery of 100 ± 3 % was obtained.

Gas-Liquid Chromatographic Determination of Residues from the Herbicide 2-Chloro-l-(3-Ethoxy-4-Nitrophenoxy)-4-(Trifluoromethyl) Benzene

1978 ◽  
Vol 61 (3) ◽  
pp. 636-639 ◽  
Author(s):  
Irving L Adler ◽  
Linwood D Haines ◽  
Brent Marco Jones
Keyword(s):  
Liquid Chromatography ◽  
Sodium Hydroxide ◽  
Methanol Extract ◽  
Chromatographic Determination ◽  
Extraction Process ◽  
Gas Liquid Chromatography ◽  
Simultaneous Distillation Extraction ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Residues of 2 - chloro - 1 - (3 - ethoxy- 4 - nitrophenoxy)-4-(trifluoromethyl) benzene and reduced metabolites are determined by digesting a sample methanol extract with aluminum in aqueous 10% sodium hydroxide to convert residues to 4-[2-chloro-4-(trifluoromethyl)-phenoxy]-2-ethoxybenzenamine. This compound is partitioned into hexane, using a simultaneous distillation-extraction process. The heptafluorobutyryl derivative is then prepared, partially purified by chromatography on Florisil, and measured by electron capture gas-liquid chromatography. The method is sensitive to 0.01 ppm.

Gas-Liquid Chromatographic Determination of β-Asarone in Wines and Flavors

1976 ◽  
Vol 59 (3) ◽  
pp. 675-677
Author(s):  
Randolph H Dyer ◽  
Glenn E Martin ◽  
Peter C Buscemi
Keyword(s):  
Liquid Chromatography ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Ethyl Palmitate ◽  
Ultraviolet Spectra ◽  
Liquid Chromatographic Determination ◽  
Mass Spectrometery ◽  
Liquid Chromatographic

Abstract Wine samples containing β-asarone (cis-2,4,5-trimethoxy-1-propenylbenzene) are distilled; β-asarone is extracted by hexane and then quantitatively determined by gas-liquid chromatography (GLC), using ethyl palmitate as the internal standard. The GLC procedure is rapid and yields precise and accurate results. Mass spectrometery confirmed the identity of the GLC peak as β-asarone. The ultraviolet spectra of β-asarone and its isomer were also determined.

Gas-Liquid Chromatographic Determination of p-Chloroacetanilide in Acetaminophen

1978 ◽  
Vol 61 (1) ◽  
pp. 68-71
Author(s):  
Dorothy K Wyatt ◽  
Lee T Grady
Keyword(s):  
Liquid Chromatography ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Flame Ionization ◽  
Glass Column ◽  
Retention Characteristics ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Gas-liquid chromatography (GLC) coupled with column chromatography was used to accurately determine as little as 25 ppm p-chloroacetanilide in acetaminophen. p-Chloroacetanilide was eluted from a pH 8 phosphate-buffered diatomite partition column by using purified tetrachloroethylene (acetaminophen was retained). This solution was concentrated, internal standard (docosane) was added, and p-chloroacetanilide was determined by using a 0.9 m × 2 mm glass column packed with 3% Poly A 103 on Supelcoport and a flame ionization detector with electronic integration. Standard curves were linear for 10–100 ppm p-chloroacetanilide. Various chromatographic materials were investigated for optimal retention characteristics. High pressure liquid chromatography (HPLC) was also evaluated as an alternative; however, lack of reproducibility of the HPLC column favored the GLC procedure.

Gas-Liquid Chromatographic Determination of Permethrin in Bovine Tissues

1979 ◽  
Vol 62 (6) ◽  
pp. 1309-1311
Author(s):  
Delbert D Oehler
Keyword(s):  
Liquid Chromatography ◽  
Electron Capture ◽  
Chromatographic Determination ◽  
Chromatographic Column ◽  
Gas Liquid Chromatography ◽  
Florisil Column ◽  
Bonded Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is presented for the determination of permethrin (m-phenoxybenzyl cis,trans-(±)-3-(2,2-dichlorovinyl) - 2,2 - dimethylcyclopropanecarboxylate) in bovine tissues. Fat and muscle samples were cleaned up first by liquid-liquid partition on a bonded phase chromatographic column. Final cleanup of fat and muscle was performed on a short Florisil column. Liver, kidney, spleen, and heart tissues only required cleanup on a Florisil column before quantitation of permethrin by electron capture gas-liquid chromatography.

Gas-Liquid Chromatographic Determination of Residues of Chlorpyriphos and Leptophos, Including their Major Metabolites, in Vegetable Tissue

1974 ◽  
Vol 57 (1) ◽  
pp. 182-188 ◽  
Author(s):  
Heinz E Braun
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Aqueous Sodium ◽  
Hydrolysis Products ◽  
Aqueous Sodium Carbonate ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Hydrolysis Of

Abstract A method is described for the determination of residual chlorpyriphos (O, O-diethyl 0-3,5,6- trichloro- 2 - pyridyl phosphorothioate) and leptophos (O-(4-bromo-2,5-dichlorophenyl) O-methyl phosphonothioate), and their respective oxygen analogs and hydrolytic metabolites, in field-treated vegetables. Samples are extracted by blending with acetonitrile followed by liquid-liquid partitioning between benzene and aqueous sodium carbonate to separate the parent compounds and oxygen analogs from the hydrolytic metabolites. Both fractions are individually cleaned up on silica gel which also serves to fractionate the parent compounds from their oxygen analogs as the result of oncolumn hydrolysis of the oxygen analogs. Chlorpyriphos and leptophos are determined by flame photometric gas-liquid chromatography (GLC); the residual and derived hydrolysis products are derivatized with trimethylsilyl acetamide and determined by electron capture GLC. Overall recoveries from fortified samples averaged 95% for the parent compounds and 85% for the oxygen analogs and hydrolytic metabolites. Detection limits approximated 0.005 ppm for chlorpyriphos and leptophos, 0.002 ppm for the oxygen analogs, and 0.001 ppm for the hydrolytic metabolites.

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