摘要:

The totalN‐nitroso content of foods can be measured by chemical denitrosation with hydrogen bromide and chemiluminescence detection of the cleaved nitric oxide radical. The denitrosation reagent itself causes a significant detector response which has limited the application of the technique to trace analysis. A procedure is described in which the errors associated with this interference are minimized. Application of this method to the trace analysis of aqueous and solid samples is reported together with an investigation of the effects of sample size on the accuracy and sensitivity of the assay as applied to aqueous analytes. The magnitude and significance of the false‐positive response from nitrate is discussed in relation to the analysis of cured meats.

ISSN:0265-203X    

DOI:10.1080/02652038409385850

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Procedures are described for the use of high‐performance liquid chromatography and gas chromatography with a chemiluminescence detector in the analysis ofN‐nitrosoamino acids,N‐nitrosothiazolidine‐4‐carboxylic acid,N‐nitroso‐oxazolidine‐4‐carboxylic acids andN‐nitroso dipeptidesN‐terminal inN‐nitrosoproline in cured meat products. The detection limit is around 5–10μg/kg. Evidence is presented for the presence of all these species except theN‐nitrosated dipeptides.

ISSN:0265-203X    

DOI:10.1080/02652038409385851

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

3H‐trienbolone acetate (TBA) was injected/implanted in cattle and the distributionofradioactivity in liver and muscular tissue was determined, applying rigorously standardized organic or aqueous extraction procedures, either directly or following enzymatic hydrolysis and proteolytic procedures. These steps yielded almost 100% recovery of the radioactivity and indicated that only between 5% and 15% of the total residues present was extractable with organic solvents. The remaining radioactivity was either soluble in aqueous media or stayed bound to tissue structures. Similarly processed liver tissue from a calf treated with 3500 mg TBA 68 days prior to slaughter was examined by applying radioimmunoassay for the determination of TBA/trienbolone (TBOH). Indications of the presence of trienic‐steroid type residues were only obtained for fractions containing residues extractable with organic solvents.

ISSN:0265-203X    

DOI:10.1080/02652038409385852

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Four experiments were carried out with veal calves which were implanted subcutaneously with Synovex‐H. Testosterone in blood plasma and also total oestrogens in plasma, urine and faeces during the trial and in liver, kidney and muscle after slaughter (62–75 days after implantation) were determined. Prepurification methods and radioimmunoassays for faeces and tissue samples were elaborated and validated. Variables between or within the trials were the sex, the dose (four pellets versus eight pellets; 25 mg testosterone propionate + 2.5 mg 17β‐oestradiol‐3‐benzoate per pellet) and the implantation site (either on the base of the ear or on the middle of the pinna). Results from the blood plasma and the excreta showed that using four pellets implanted in the middle of the pinna guaranteed a continuous release in order that oestrogen levels were maximally doubled in comparison to controls. On the other hand, application of the same dose at the base of the ear was characterized by an accentuated burst during the first three days (10‐fold elevation over controls). In plasma and excreta of male controls, higher oestrogen concentrations were measured as compared to the corresponding substrates of females. Comparing all groups, untreated males showed the highest testosterone levels. In all animals, residues of total oestrogens were of the same order of magnitude (kidney and liver 01–1.5 ng/g; muscle 0–32 pg/g) with somewhat higher means in the treated groups. Since all results are within the physiological scope, no risk for the consumer is visible after correct use of Synovex‐H.

ISSN:0265-203X    

DOI:10.1080/02652038409385853

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The diet is the main source of tin intake by man. Nearly all the tin in the UK diet is associated with canned food. Canned tomatoes, tomato products, pineapple, pears and similar fruits contain the highest concentrations of tin. Average dietary tin intakes in the UK are about 3 mg/day and have been falling since 1976.

ISSN:0265-203X    

DOI:10.1080/02652038409385854

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Three flavourings: dimethyl succinate, ethyl pyruvate and aconitic acid, commonly used in candy, beverages, and baked goods, were tested in theSalmonella/mammalian‐microsome test. Tester strains were TA 1535, TA 100, TA 1537 and TA 98 and doses were 32, 160, 800, 4000 and 20 000 μg, per plate. All tests were performed with and without the S9 fraction from Aroclor induced rat liver. None of the flavourings showed mutagenic potential. These results support the classification made by the Council of Europe, List I (1981).

ISSN:0265-203X    

DOI:10.1080/02652038409385855

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The content of individual glucosinolates in 32 samples of cabbage (representing 21 cultivars), 11 samples of Savoy cabbage (seven different cultivars), 33 samples of swede (16 cultivars) and nine samples of turnip (three cultivars) have been determined by gas chromatography. 2‐Propenyl, 3‐methylsulphinyl and 3‐indolylmethyl glucosinolates were the predominant compounds in both types of cabbage, with the Savoy cabbage showing a mean total glucosinolate content more than double that of white cabbage (209 vs. 90mg/100g fresh weight). The glucosinolate content of the swede and turnip samples was more complex, with 2‐hydroxy‐3‐butenyl‐glucosinolate predominating in swedes and this compound, 3‐butenyl‐and 2‐phenylethyl‐glucosinolates being the major components of turnip. The mean total glucosinolate contents of swede and turnip were 92 and 93 mg/100 g fresh weight. Compared to published data on American vegetables, the UK cabbage samples were much richer in glucosinolates and the UK swede and turnip samples poorer in glucosinolates. Swede rind was observed to be a particularly good source of indolyl glucosinolates, the anticarcinogenic properties of which are presently under investigation.

ISSN:0265-203X    

DOI:10.1080/02652038409385856

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Analysis of Food Contaminants.Edited by J. Gilbert. (Elsevier‐Applied Science, London, 1984), pp. xiv + 386. £40.00. ISBN 0–85334–225–5.

ISSN:0265-203X    

DOI:10.1080/02652038409385857

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0265-203X    

DOI:10.1080/02652038409385849

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor