Comparison of methods for the determination of carotene
No abstract available.
Journal of the Association of Official Analytical ↗
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Procedure for the analysis of zinc phosphide rodenticides
No abstract available.
Journal of the Association of Official Analytical ↗
Gas chromatographic separation and quantitative estimation of barbiturate mixtures in solid dosage forms
A gas chromatographic method has been described for the analysis of mixed barbiturates in solid dosage forms. Analysis on a 10% SE-30 column gave good separations for butabarbital, amobarbital, secobarbital, pentobarbital, and/or phenobarbital; amobarbital is not separated adequately from pentobarbital. An internal standard, mephobarbital, is used to minimize injection errors. The method gives both good quantitative and qualitative results on the barbiturates investigated. Two synthetic tablet mixtures were analyzed by this procedure and recoveries were 98—103%. It is recommended that the method be subjected to collaborative study.
Journal of the Association of Official Analytical ↗
GLC determination of quinaldine residue in fish
A procedure for the determination of quinaldine residue in various fish tissues is described. Homogenized tissues are extracted with hexane-ethyl ether, the extracts are concentrated by partitioning through 0.1N sulfuric acid, and the residues are measured by alkali flame ionization gas chromatography. Muscle tissues containing from 0.01 to 10.0 ppm quinaldine were successfully analyzed with recoveries from 75 to 100%.
Journal of the Association of Official Analytical ↗
Identification of polychlorinated biphenyls in two bald eagles by combined gas-liquid chromatography-mass spectrometry
Polychlorinated biphenyls are widely used industrial compounds marketed in the United States under the trade name Aroclor. They have appeared in fish and wildlife tissues in this country and Europe. They are known to be toxic, but more importantly, their presence in samples along with the commonly occurring organochlorine pesticides complicates the analysis to a serious degree, making identification of pesticide residues by GLC without preliminary separation extremely unreliable. Residues of both polychlorinated biphenyls and organochloride pesticides were present in eagle carcasses. Many of the polychlorinated biphenyl components had retention times identical with those of certain organochlorine pesticide residues. Identification was accomplished by preliminary separations on thin layer plates followed by combined GLC- mass spectromtry.
Journal of the Association of Official Analytical ↗
UV identification and quantitative measurement of quinaldine residues in fish
A method for the confirmatory analysis of quinaldine residue in fish is described. The method utilizes the same extraction and cleanup procedure as the GLC method reported previously. The lower limit of sensitivity for quinaldine residue in fish muscle is 0.01 ppm. Identification is accomplished by comparing the UV spectra of the sample and a standard solution of quinaldine.
Journal of the Association of Official Analytical ↗
Semiquantitative determination of polychlorinated biphenyls in tissue samples by thin layer chromatography
A method is described for the analysis of polychlorinated biphenyl (PCB) compounds in tissue samples. Cleanup by hexane-acetonitrile partitioning and Florisil column chromatography are performed on samples before oxidative treatment to convert DDE to DCBP. PCB components are then determined semi-quantitatively by TLC. No prior separation of PCB from chlorinated pesticides is required. The lower limit of sensitivity is 0.2 μ g.
Journal of the Association of Official Analytical ↗
Versatile combustion-amalgamation technique for the photometric determination of mercury in fish and environmental samples
Total mercury in a variety of substances is determined rapidly and precisely by direct sample combustion, collection of released mercury by amalgamation, and photometric measurement of mercury volatilized from the heated amalgam. Up to 0.2 g fish tissue is heated in a stream of O 2 (1.2 L/min) for 3.5 min in 1 tube of a 2-tube induction furnace. The released mercury vapor and combustion products are carried by the stream of O 2 through a series of traps (6% NaOH scrubber, water condenser, and Mg(ClO 4 ) 2 drying tube) and the mercury is collected in a 10 mm diameter column of 24 gauge gold wire (8 g) cut into 3 mm lengths. The resulting amalgam is heated in the second tube of the induction furnace and the volatilized mercury is measured with a mercury vapor meter equipped with a recorder-integrator. Total analysis time is approximately 8 min/sample. The detection limit is less than 0.002 μ g and the system is easily converted for use with other biological materials, water, and sediments.
Journal of the Association of Official Analytical ↗
Gas-liquid chromatographic determination of kepone in field-collected avian tissues and eggs
A procedure is described for determining Kepone (decachlorooctahydro-l,3,4-metheno-2H-cyclobuta [cd]pentalene-2-one) residues in avian egg, liver, and tissue. Samples were extracted with benzene-isopropanol, and the extract was cleaned up with fuming H 2 SO 4 -concentrated H 2 SO 4 . Kepone was separated from organochlorine pesticides and polychlorinated biphenyls on a Florisil column and analyzed by electron capture gas-liquid chromatography GLC). The average recovery from spiked tissues was 86%. The analyses performed on 14 bald eagle carcasses and livers, 3 bald eagle eggs, and 14 osprey eggs show measurable levels which indicate that Kepone accumulates in the tissues of fish-eating birds. Residues were confirmed by GLC-mass spectrometry.
Journal of the Association of Official Analytical ↗
Gas-liquid chromatographic and gas-liquid chromatographic-mass spectrometric determination of fenvalerate and permethrin residues in grasshoppers and duck tissue samples
A procedure is described for determining fenvalerate and permethrin residues in grasshoppers and duck tissues. Samples are Soxhlet-extracted with hexane and cleaned up by gel permeation chromatography with an in-line alumina column. Samples are analyzed by gas-liquid chromatography with electron capture detection, and confirmed by gas-liquid chromatography-mass spectrometry. The average recovery from fortified tissues was 97%.
Journal of the Association of Official Analytical ↗
Residues of organochlorine insecticides, polychlorinated biphenyls, and heavy metals in biota from Apalachicola River, Florida, 1978
Seventy-seven composite samples composed of largemouth bass ( Micropterus salmoides ), channel catfish ( Ictaluras punctatus ), threadfin shad ( Dorosoma petenense ), Asiatic clam ( Corbicula fluminea ), burrowing mayfly ( Hexagenia sp.), water snake ( Natrix spp.), and little green heron ( Butorides virescens ) were collected from upper and lower reaches of the Apalachicola River, Florida, in 1978 for residue analysis of organochlorine insecticides, PCBs (polychlorinated biphenyls), and metals. Compared with data from the National Pesticide Monitoring Program and criteria recommended for the protection of aquatic life, residue concentrations were moderately high in the Apalachicola River. Biota from the upper river generally had higher organic and lower metal residues than those from the lower river. Highest residues in the biota were total DDT, total PCBs, and toxaphene. Although individual mean concentrations were below 2 μg/g and total organic contaminant residues never exceeded 5 μg/g, residue concentrations of DDT, PCBs, and toxaphene (particularly from the upper river) exceeded recommended permissible levels for the protection of aquatic life. Metal residues were generally below 1 μg/g. Exceptions were arsenic residues in threadfin shad (1.07 μg/g) and Asiatic clams (1.75 μg/g), and selenium in eggs of channel catfish (1.39 μg/g). The residues observed in the biota, particularly from the upper station, indicated moderate contamination of the Apalachicola River system at the time samples were collected.
Journal of the Association of Official Analytical ↗
Monocrotophos and dicrotophos residues in birds as a result of misuse of organophosphates in Matagorda county Texas USA
About 1100 birds of 12 spp. [Red-winged blackbird ( Agelaius phoeniceus ), great-tailed grackle ( Quiscalus mexicanus ), brown-headed cowbird ( Molothrus ater ), mourning dove ( Zenaida macrours ), Eastern meadowlark ( Sturnella magna ), vesper sparrow ( Pooecetes gramineus ), common snipe ( Gallinago gallinago ), blue-winged teal ( Anas discors ), mottled duck ( Anas fulvigula ), common moorhen ( Gallinula chloropus ), redhead ( Aythya americana ) and ruddy turnstone ( Arenaria interpres )] died from organophosphate poisoning in Matagorda County on the Texas Gulf Coast in March and May 1982. Birds died from feeding on rice seed that was illegally treated with dicrotophos or monocrotophos and placed near rice fields as bait to attract and kill birds. Brain acetylcholinesterase inhibition of affected birds averaged 87% (range 82-89%), and contents of gastrointestinal tracts contained residues of dicrotophos (5.6-14 ppm) or monocrotophos (2.1-13 ppm). Rice seed collected at mortality sites contained 210 ppm dicrotophos or 950 ppm monocrotophos. Mortality from dicrotophos poisoning continued for almost 3 wk. The practice of illegally treating rice seed with either of the 2 organophosphates appears to be infrequent but widespread at present.
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Combined extraction-cleanup column chromatographic procedure for determination of dicofol in avian eggs
Dicofol in avian eggs was completely oxidized to dichlorobenzophenone (DCBP) when a hexane Soxhlet extraction procedure was used. This degradation did not occur with other avian tissues (muscle and liver). For this reason, a combined extraction-cleanup column chromatographic procedure, without added heat, was developed for the determination of dicofol in avian eggs. Homogenized subsamples of eggs were mixed with sodium sulfate, and the mixture was added as the top layer on a column prepacked with Florisil. The dicofol and other compounds of interest were then eluted with ethyl etherhexane. The extracts, relatively free from lipids, were quantitated on a gas chromatograph equipped with a 63Ni electron-capture detector and a methyl silicone capillary column. Recoveries from chicken eggs, fortified with dicofol and other DDT-related compounds, averaged 96%. Analysis of eggs of eastern screech-owls, fed a meat diet containing 10 ppm technical Kelthane, showed that both dicofol and DCBP were present. Results were confirmed by gas chromatography/ mass spectrometry. This method is rapid and reliable, involves a minimum of sample handling, and is well suited for high volume determination of dicofol in eggs and other avian tissues .
Journal of the Association of Official Analytical ↗
Liquid-chromatographic determination of rotenone in fish, crayfish, mussels, and sediments
An analytical procedure is described for determining residues of rotenone in fish muscle, fish offal, crayfish, freshwater mussels, and bottom sediments. Tissue samples were extracted with ethyl ether and extracts were cleaned up by gel permeation chromatography and silica gel chromatography. Sediment samples were extracted with methanol, acidified, partitioned into hexane, and cleaned up on a silica gel column. Rotenone residues were quantitated by liquid chromatography, using ultraviolet (295 nm) detection. Recoveries from sediment samples fortified with rotenone at 0.3 μg/g were 80.8%, whereas recoveries from tissue samples fortified with 0.1 μg/g ranged from 87.7 to 96.8%. Samples fortified with 0.3 μg/g and stored at - 10°C for 6 months before analysis had recoveries ranging from 83.2 to 90.5%. Limits of detection were 0.025 μg/g for sediments and 0.005 μg/g for tissue samples.
Journal of the Association of Official Analytical ↗
Determination of monocyclic and polycyclic aromatic hydrocarbons in fish tissue
No abstract available.
Journal of the Association of Official Analytical ↗
Improved selenium recovery from tissue with modified sample decomposition
The present paper describes a simple modification of a recently reported decomposition method for determination of selenium in biological tissue by hydride generation atomic absorption. The modified method yielded slightly higher selenium recoveries (3-4%) for selected reference tissues and fish tissue spiked with selenomethionine. Radiotracer experiments indicated that the addition of a small volume of hydrochloric acid to the wet digestate mixture reduced slight losses of selenium as the sample initially went to dryness before ashing. With the modified method, selenium spiked as selenomethionine behaved more like the selenium in reference tissues than did the inorganic spike forms when this digestion modification was used.
Journal of the Association of Official Analytical ↗