摘要:

The objective of this study was to develop an analytical approach to determine whether the illegal application of clenbuterol in cattle as an anabolic agent can be concealed by co‐treatment with substances that affect urinary excretion. Female veal calves were dosed orally with 0.8 μg clenbuterol per kg of body weight twice daily for 28 days, as licensed for the therapeutic use which is registered in most European countries. On the eighth day of clenbuterol treatment each calf was additionally dosed orally either with probenecid, sulfinpyrazone or pyrazinamide at three different doses that were increased in weekly intervals. During the treatment blood and urine samples were obtained and analysed for clenbuterol by enzyme immunoassay and by high performance liquid chromatography/ enzyme immunoassay to determine whether these drugs or their metabolites interfered with the immunological detection of clenbuterol. Clenbuterol could be detected in plasma (∼200 pg ml−1) and urine (1–40 ng ml−1) 5 h after the initial intake and throughout the whole treatment. None of the drugs reduced urinary excretion of clenbuterol to concentrations below the limit of detection. There was no prevention of clenbuterol detection in urine samples from calves that were co‐treated with the drugs tested in this study. Our results demonstrate the uselessness of applying these drugs in order to conceal the illegal use of clenbuterol in meat production.

ISSN:0265-203X    

DOI:10.1080/02652039609374445

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The use of pesticides has been monitored on the basis of sales statistics since 1953 in Finland and the information has been used for targeting the official food control to products where pesticides are mostly used. Food consumption and the earlier control results were also taken into account. The intake of pesticides has been estimated based on the control analysis and statistical food consumption data, where also the ratio of imports was taken into account. The samples were taken by food control authorities and analysed separately. In spite of slight bias owing to sampling for control purposes, the results are representative of the products consumed. The intake estimation method has been classified in the group Estimated Daily Intake (EDI). The intakes of a total of the 53 most commonly found pesticides were estimated. The intakes of the evaluated pesticides were below 2% of ADIs. The average daily intake was 75 μg per person in 1992 mainly from imported products, only 24% initiating from domestic products. The intake of pesticides from domestic vegetables, fruits and berries has been evaluated three times during 1977–1993. The daily intake of pesticide residues from these products has decreased from 16.9 μg to 3.7 μg. The intensive food control has decreased offences against the regulations. The method used seems to be suitable for the longterm monitoring. The average intake of pesticides is at a low level compared with the Acceptable Daily Intakes, thus further estimations by more defined methods are not necessarily neeeded. The advantage of the method adopted is that residue data can also be used to make more accurate Measured Daily Intake estimates for risk groups such as children and vegetarians.

ISSN:0265-203X    

DOI:10.1080/02652039609374446

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Bromate can be formed as a by‐product of ozone treatment that is sometimes used for the disinfection of municipal water supplies and bottled waters. The US Environmental Protection Agency has proposed a maximum contaminant level (MCL) of 10 μg/l for bromate in public drinking water. Should the proposed MCL for bromate become final, it may then be considered for adoption as a bottled water quality standard by the US Food and Drug Administration. This paper reports the development of a gas chromatographic/ mass spectrometric (GC/MS) method for the determination of parts‐per‐billion (μg/l) levels of bromate (BrO−3in bottled water. The GC/MS method was validated by using distilled and deionized Milli‐Q® water; detection limits, quantitation limits, and recoveries were determined and identities were confirmed by MS on the basis of analyses of test portions fortified with BrO−3at 0.8, 3.8, 7.7, 15, and 46 μg/l. The method also was evaluated on the basis of recoveries determined for two commercial brands of bottled water fortified with BrO−3at 3.8 and 7.7 μg/l and two commercial brands fortified at 0.8, 3.8, and 7.7 μg/l. For the Milli‐Q® water, recoveries ranged from 100 to 121%; for the fortified commercial products, recoveries Tanged from 87 to 115%. The limits of detection and quantitation were determined to be 0.4 and 0.7 μg/l, respectively. Several commerical brands of bottled water were analysed, and BrO−3was found in these products at levels ranging from none to 38 μg/l.

ISSN:0265-203X    

DOI:10.1080/02652039609374447

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The objective of this work was to develop a reliable, ragged high‐performance liquid chromatographic (HPLC) method for determination of trace levels of bromate (< 10 μg/l) in bottled water. HPLC separation was achieved by ion interaction chromatography using a C‐18 reversed‐phase column and a mobile phase consisting of methanol/water (20:80, v/v) with tetrabutylammonium acetate as the ion interaction reagent. A post‐column reaction based on oxidation of o‐dianisidine in acidic solution to a product detected at 500 nm provided selective measurement of the oxidants. The limit of detection and the limit of quantitation were 1 and 3 μg/l, respectively. Iodate, chlorite, and nitrite were chromato‐graphically separated from bromate and measured by monitoring the post‐column reaction. Chloride and chlorate at levels that might be found in bottled water did not interfere with the determination of bromate. Bromate was detected in bottled waters at concentrations up to 40 μg/l.

ISSN:0265-203X    

DOI:10.1080/02652039609374448

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Samples of vegetable oils on the Brazilian market including rape seed, corn, soybean, sunflower, rice, palm and garlic were analysed for benzo(a)pyrene (B(a)P). The analytical method involved liquid‐liquid extraction, clean‐up on silica gel column and determination by high performance liquid chromatography using fluorescence detection. The limit of detection was 0.5 μg/kg. Benzo(a)pyrene was detected in almost all samples, at levels up to 58.9 μg/kg. The mean levels of B(a)P in rice, sunflower, soybean, corn and palm oils were 1.8, 0.2, 2.2, 10.8 and 2.1 μg/kg respectively. No B(a)P was detected in garlic and rape seed oils. The data indicate that the levels of B(a)P found in Brazilian corn oils are relatively higher than those published in the literature for European corn oils.

ISSN:0265-203X    

DOI:10.1080/02652039609374449

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The lead and cadmium contents of the main fish species consumed in Finland were determined by ETAAS after wet digestion with HNO3. Analytical quality was controlled with blanks, reference materials and blind replicates. Mean and median lead contents of domestic fish species were <LOD (1 μg/kg)‐9·4 μg/kg and <LOD‐4.7 μg/kg. The lead contents of imported fish and imported canned or salted fish ranged from < LOD to 8, and 4 to 177 μg/kg. Mean and median cadmium contents of domestic fish species were <LOD (0.4 μg/kg)‐5·8 μg/kg and <LOD‐4.4 μg/kg. Fresh imported fish contained <LOD‐11 μg Cd per kg and canned or salted fish 9–42 μg Cd per kg. Higher fish consumption would not increase lead or cadmium intake significantly in Finland. At present fish contributes about 4% of the average lead intake and 3% of cadmium intake.

ISSN:0265-203X    

DOI:10.1080/02652039609374450

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The concentrations of ochratoxin A (OA) and C (ethyl ester of OA, OC) have been measured in table wine from the Swiss retail market. The overall median concentrations of OA in white, rosé and red table wine were (number of samples; range) < 3 pg/ml (24; < 3–178 pg/ml), 19 pg/ml (15; < 3–123 pg/ml) and 13 pg/ml (79; < 3–388 pg/ml)), respectively. For dessert wines (Malaga, Marsala) a median of 337 pg/ml (5; 44–451 pg/ml) resulted. Concentrations of OC were about 10% of those of OA. OA has been detected in red grape‐juices for the first time with median concentrations amounting to 235 pg/ml (8; < 3–311 pg/ml). White grape‐juices (3) as well as other fruit juices (2 apple, 6 orange, 2 others) did not contain OA (< 5 pg/ml). The analytical method used was not appropriate for grapefruit‐juices because of an interfering substance. The results indicate that OA is formed prior to the alcoholic fermentation. It also appears that the more southerly in Europe is the origin of the samples the higher is the frequency of occurrence and the concentration of OA in red wines and red grape‐juices. Although the estimated mean daily OA intake of 0.7 ng/kg body mass (men) can easily be more than doubled by moderate wine consumption, an additional health risk by OA is not to be expected. On the other hand the consumption of red grape‐juices among infants and children may result in intakes high enough to justify a reduction of the OA concentrations in these juices to less than 100 pg/ml.

ISSN:0265-203X    

DOI:10.1080/02652039609374451

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Samples (121) of cow's milk from a northern region of Germany were analysed for the occurrence of ochratoxin A by means of a sensitive high‐performance liquid chromato‐graphic (HPLC) method. The samples were extracted with a mixture of chloroform and methanol at pH < 2. The extracts were cleaned up by solid‐phase extraction on silica gel cartridges. The detection limit was 001 ng/ml, the quantitation limit was estimated at 0.03 ng/ml. The mean recovery from spiked samples was 84 ± 7% in the concentration range of 0.03–0.5 ng/ml. An enzyme‐linked immunosorbent‐assay (ELISA) was shown to be suitable for the confirmation of ochratoxin A levels down to the detection limit of the HPLC method. No ochratoxin A was detected in the samples analysed, either by HPLC or by ELISA.

ISSN:0265-203X    

DOI:10.1080/02652039609374452

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The distribution of total aflatoxin (AFT) and cyclopiazonic acid (CPA) between conidia and mycelial matrix was studied in five isolates ofAspergillus flavusLink cultured on maize grain for 20 days at 30°C. Total aflatoxin and CPA production differed between the isolates withAspergillus flavusF2R4FP 1–5 producing the most AFT (conidia—0.245 μg/g; mycelial matrix—83 μg/g) and CPA (conidia—0.091 μg/g; mycelial matrix—37 μg/g). The production of AFT and CPA by this isolate was compared in liquid (malt‐extract‐yeast‐extract‐glucose) and solid substrates (yeast extract sucrose agar and maize) at 30°C. The ratio of AFT:CPA in maize decreased from 16.6:1 to 1.6:1 between 7 and 21 days’ incubation. In liquid culture and yeast extract sucrose agar, the ratios were reversed and ranged from 1:3 to 1:9 and 1:22 to 1:28, respectively, the greatest difference in both media occurring after 15 days.

ISSN:0265-203X    

DOI:10.1080/02652039609374453

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Over the past 7 years, acute food poisoning arising from the consumption of methamidophos‐tainted vegetables has occurred sporadically in Hong Kong. To enable prompt remedial and regulatory actions to be taken, a simple and rapid gas Chromatographic method was developed to determine methamidophos residues in food remnants. Samples were homogenized and extracted with acetone. Acetone in the resultant extract was removed by rotary evaporation, leaving behind an aqueous solution. After washing with petroleum ether and addition of sodium sulphate, the aqueous solution was re‐extracted with chloroform. The chloroform extract was concentrated to dryness and the residue was reconstituted in absolute ethanol for determination by gas chromatography with flame photometric detection. The method was found to be applicable also to the determination of acephate, dimethoate, omethoate and trichlorfon. Mean recoveries of the five organo‐phosphorus pesticides at two fortification levels, viz. 1 mg/kg and 10 mg/kg, ranged from 74 to 113%. Relative standard deviations lay between 1.3 and 6.1%. Method detection limits ranged from 0.02 to 0.04 mg/kg. In 1994, 75 food poisoning cases in Hong Kong were suspected to be related to the consumption of methamidophos‐tainted vegetables; 13 food remnants were received for analysis, four of them were found to contain high concentrations of methamidophos.

ISSN:0265-203X    

DOI:10.1080/02652039609374454

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor