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1.
Bioanalysis ; 2(9): 1627-40, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21083291

RESUMO

The acetonitrile shortage during 2008 to 2009 challenged bioanalytical scientists due to the ubiquitous role that acetonitrile plays in sample preparation and analysis. Replacement, reduction and reuse of acetonitrile were the core tenants behind each approach used to tackle the shortage. Sample preparation of biological matrices can be accomplished by protein precipitation using a variety of solvents; methanol is usually the best substitute for acetonitrile. The potential liabilities in using methanol can be handled with appropriate modifications. Often methanol is superior to acetonitrile for both protein precipitation and chromatography if phospholipid interference is a problem. Solvent consumption can be minimized by reducing column dimensions and particle size. Separations can be achieved at greatly reduced run times using sub-2-µm and fused-core particle columns. Emerging technologies, such as desorption ESI, direct analysis in real time and laser diode thermal desorption, eliminate the need for chromatography and achieve significant solvent and time savings. Acetonitrile recyclers can purify HPLC waste for reuse.


Assuntos
Acetonitrilas/provisão & distribuição , Técnicas de Química Analítica/métodos , Acetonitrilas/química , Animais , Fracionamento Químico , Humanos , Solventes/química , Solventes/provisão & distribuição
3.
J AOAC Int ; 88(5): 1383-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16385986

RESUMO

A rapid extraction technique was developed for the isolation and subsequent liquid chromatographic determination of aflatoxins B1, B2, G1, and G2 in creamy and crunchy peanut butter. Peanut buftter samples were extracted with a methanol 15% sodium chloride (7 + 3) solution followed by a second extraction with methanol. The extract was subjected to a cleanup using a Vicam Aflatest immunoaffinity column. Control samples for both smooth and crunchy peanut butter were fortified at 4 different levels for aflatoxin B1, B2, G1, and G2. The average aflatoxin B1, B2, G1, and G2 recoveries from smooth peanut buffer were 95.2, 89.9, 94.1, and 62.4%, respectively, and 92.4, 84.3, 85.5, and 53.7%, respectively, from crunchy peanut butter. This extraction method and the official AOAC Method 991.31 produced comparable results for peanut butter samples. This method provides a rapid, specific, and easily controlled assay for the analysis of aflatoxins in peanut butter with minimal solvent usage. Organic solvent consumption was decreased by 85% and hazardous waste production was decreased by 80% in comparison with the AOAC method. Along with the decreased solvent consumption, significant savings in time were observed.


Assuntos
Aflatoxinas/isolamento & purificação , Arachis/química , Cromatografia Líquida/métodos , Análise de Alimentos/métodos , Resíduos Perigosos , Padrões de Referência , Solventes/provisão & distribuição
4.
BMJ ; 310(6971): 20-4, 1995 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-7755714

RESUMO

OBJECTIVE: To monitor young people's knowledge and experience of illicit drugs between 1969 and 1994 at intervals of five years. DESIGN: The same anonymously completed questionnaire was used throughout. SETTING: Three Wolverhampton secondary schools representing three different socioeconomic groups. SUBJECTS: 392 pupils aged 14 to 15 completed the questionnaire in 1994. Previous sample sizes were 471 in 1969, 523 in 1974, 648 in 1979, 540 in 1984, and 380 in 1989. MAIN OUTCOME MEASURES: Self reported levels of knowledge and experience of illicit drugs. RESULTS: Over 25 years the proportion of pupils who knew someone taking drugs more than quadrupled from 15% (71/471) to 65% (254/392), and the proportion who had been offered drugs increased ninefold from 5% (24) to 45% (175). Both of these proportions more than doubled over the past five years. In 1994 the proportions of pupils mentioning "ecstasy" (methylenedioxymethamphetamine), amphetamines, and crack cocaine increased significantly (P < 0.01) and the proportion mentioning opiates decreased significantly (P < 0.01). "Poppers" (amyl nitrite) were mentioned for the first time. "To feel big, to show off, look grown up" has continued to be the main perceived reason for taking drugs. Television has continued to be the main source of information. CONCLUSIONS: In the past five years in particular young people's exposure to illicit drugs has increased dramatically. Despite more education about drugs, pupil's knowledge remains limited. Social pressures remain the first perceived reason for taking drugs. The media have a responsibility not to glamorise drugs.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Drogas Ilícitas/provisão & distribuição , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adolescente , Anfetaminas/provisão & distribuição , Drogas Desenhadas/provisão & distribuição , Inglaterra/epidemiologia , Feminino , Educação em Saúde , Humanos , Drogas Ilícitas/efeitos adversos , Dietilamida do Ácido Lisérgico/provisão & distribuição , Masculino , Fumar Maconha/tendências , Entorpecentes/provisão & distribuição , Solventes/provisão & distribuição , Transtornos Relacionados ao Uso de Substâncias/complicações , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
5.
Sangyo Igaku ; 26(6): 518-38, 1984 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-6536775

RESUMO

A total of 1,179 organic solvent products used as thinners, paint, degreasers, inks, adhesive and others, were collected nationwide from factories of various sizes and kinds in Japan, and analyzed by gas chromatography. Solvent components per sample, frequency of each solvent component, and contents of each component were analyzed and classified by use. Paints, inks, and adhesives which contained nonvolatile substances were analyzed by head space techniques. Seventy-seven percent of all samples, 93% of paints, 85% of thinners, 73% of adhesives, and 52% of degreasers contained mixed organic solvents. The average numbers of solvent components per sample were 4.14 (max. 13) in thinner, 3.29 (max. 7) in paint, 2.23 (max. 5) ink, 2.19 (max. 6) in adhesive, 1.71 (max. 6) in degreaser, when gasoline was excluded. Toluene, xylene, methylalcohol, isopropylalcohol, ethylacetate, methylethylketone, industrial gasoline were widely used in the above-mentioned products. Toluene was the most popular component in the solvent products, excluding degreasers. Many kinds of solvent components were used in thinner and paint. However, toluene, xylene and industrial gasoline were their main components and contents per sample were very high. Acetates, alcohols, ketones and glycols were frequently detected in solvent products, but their contents per sample were relatively low, because these solvent components were usually used as subordinate solvents. The chlorinated hydrocarbons such as trichloroethylene, tetrachloroethylene and 1,1,1-trichloroethane, and industrial gasoline were the most popular components in degreasers. 1,4-dioxane was detected in a relatively large number of the samples, but its content per sample was very low, because it is usually used as an additive to 1,1,1-trichloroethane. Toluene was the most popular component in ink solvents, too. In addition, isopropylacohol, methylalcohol, methylethylketone were frequently detected in inks. Toluene was also the most popular component in adhesives, and n-hexane was also frequently detected in them. In order to prevent poisoning by industrial solvents, special attention should be paid to toluene and xylene, which are frequently and largely used for wide purposes, trichloroethylene which is largely used as a degreaser and has a severe toxicity, n-hexane which is frequently used in adhesives and has a high volatility and severe neurotoxicity, and other popular and toxic solvents. The severely toxic solvents such as benzene, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane and carbon disulfide were detected in few samples.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Solventes/análise , Adesivos/análise , Cromatografia Gasosa , Detergentes/análise , Tinta/análise , Pintura/análise , Solventes/provisão & distribuição
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