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1.
The migration of trimellitic acid and its esters from epoxy anhydride coatings was determined in simulants as well as in canned foods. The most appropriate simulant was a combination of EC simulants B and C: 2% acetic acid/10% ethanol in water. The average migration into food was 900 μg kg-1. This far exceeds the 50 μg kg-1 for which the safety of trimellitic acid and its anhydride is ensured and the Swiss legal limit (QM(T) of 5 mg kg-1 coating). Furthermore, much trimellitic acid migrated as (unidentified) esters, i.e. toxicological testing of free trimellitic acid is inadequate for the material that in reality migrates.  相似文献   

2.
Low level intake of drugs from the ingestion of contaminated feed may lead to residue problems in food animals. Sulfadimidine (SDD) was used as a model to determine the residue risk at various doses in laying hens. The drug was administered as a single intravenous injection (100 mg kg-1 body weight, BW), as a single oral dose (100, 30, 10, 3, 1 mg kg-1 BW) and via medicated feed for 7 consecutive days (30, 10, 3 mg kg-1 BW). Drug levels were determined with HPLC-UV for plasma, yolk and albumen. Pharmacokinetic values, which were calculated using a first-order one-compartment model, residue levels and transfer rates into the eggs were found to be dose-dependent. Even low doses of 3 and 1 mg kg-1 BW resulted in measurable residues in yolk and albumen 1 day after a single oral administration. After ingestion of medicated feed at 3 mg kg-1 BW, mean drug levels at 0.14 ± 0.01 µg g-1 were found in albumen and at 0.09 ± 0.01 µg ml-1 in plasma. Generally, the residue levels in albumen and plasma were higher than in yolk. These findings demonstrate a residue risk for the consumer even after low level intake of drugs.  相似文献   

3.
4.
A simple and feasible method is described for analysing nine mycotoxins in cheese matrix. The method involves liquid extraction followed by high performance liquid chromatographic separation and mass spectrometric detection of the analytes, and allows the determination of aflatoxins B1, B2, G1, G2 and M1, ochratoxin A, mycophenolic acid, penicillic acid and roquefortine C simultaneously. Average recoveries of the mycotoxins from spiked samples at concentration levels of 5-200 µg kg-1 ranged from 96-143%. Within-day relative standard deviations at these concentration levels varied from 2.3-12.1%. The limit of quantification for aflatoxin M1 was 0.6 µg kg-1 and for the other compounds 5 µg kg-1. The method developed was applied for analysing these mycotoxins in blue and white mould cheeses purchased from Finnish supermarkets. Roquefortine C was detected in all of the blue mould cheese samples in concentrations of 0.8-12 mg kg-1. One blue cheese contained also 0.3 mg kg-1 mycophenolic acid. The other investigated mycotoxins were absent in the samples.  相似文献   

5.
The European Union Baby Food Directive (1999/39/EC), which came into force on 1 July 2002, set legal maximum residue levels at 0.01 mg kg-1 for all pesticides in baby foods. The combination of large volume-difficult matrix introduction (LV-DMI) with gas chromatography-time of flight-mass spectrometry (GC-TOF-MS), described herein, provides the analyst with a simple but rapid alternative GC-MS technique for the multiresidue analysis of pesticides in fruit-based baby foods. Samples were extracted with ethyl acetate in the presence of Na2SO4 and NaHCO3 and the crude extracts were analysed directly using LV-DMI-GC-TOF-MS. The best overall results (98 pesticides quantified satisfactorily at a spiking level of 0.01 mg kg-1) were obtained by analysis of concentrated extracts (2.5 g crop ml-1) using a 30-m column, with a chromatographic run time of 25 min. A good signal-to-noise ratio was obtained at the lowest calibrated level (0.0125 μg ml-1), with excellent linearity achieved over the range 0.0125-0.25 μg ml-1 (equivalent to 0.005-0.1 mg kg-1). Average recoveries for the analysis of five replicate determinations at a spiking level of 0.01 mg kg-1 were between 79 and 114% with relative standard derivations generally less than 20%.  相似文献   

6.
Arsenic contamination of rice plants by arsenic-polluted irrigation groundwater could result in high arsenic concentrations in cooked rice. The main objective of the study was to estimate the total and inorganic arsenic intakes in a rural population of West Bengal, India, through both drinking water and cooked rice. Simulated cooking of rice with different levels of arsenic species in the cooking water was carried out. The presence of arsenic in the cooking water was provided by four arsenic species (arsenite, arsenate, methylarsonate or dimethylarsinate) and at three total arsenic concentrations (50, 250 or 500 µg l-1). The results show that the arsenic concentration in cooked rice is always higher than that in raw rice and range from 227 to 1642 µg kg-1. The cooking process did not change the arsenic speciation in rice. Cooked rice contributed a mean of 41% to the daily intake of inorganic arsenic. The daily inorganic arsenic intakes for water plus rice were 229, 1024 and 2000 µg day-1 for initial arsenic concentrations in the cooking water of 50, 250 and 500 µg arsenic l-1, respectively, compared with the tolerable daily intake which is 150 µg day-1.  相似文献   

7.
In October and November 2004, 91 spice samples (70 ground red pepper, six black pepper, five white pepper, five spice mix and five chilli samples), the majority of which originated from commercial outlets, were analysed for aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1, AFG2) and ochratoxin A (OTA) content by high-performance liquid chromatography (HPLC) after immunoaffinity column clean-up. Eighteen of the 70 ground red pepper samples contained AFB1, seven of them in a concentration exceeding the 'maximum level' of 5 µg kg-1 (range 6.1-15.7 µg kg-1). Of the other spices assayed, the AFB1 contamination of one chilli sample exceeded 5 µg kg-1 (8.1 µg kg-1). Thirty-two of the 70 ground red pepper samples contained OTA, eight of them in a concentration exceeding the 10 µg kg-1 'maximum level' (range 10.6-66.2 µg kg-1). One chilli sample was contaminated with OTA at 2.1 µg kg-1. The AFB1 and OTA contamination of ground red pepper exceeding the 'maximum level' (5 and 10 µg kg-1, respectively) was obviously the consequence of mixing imported ground red pepper batches heavily contaminated with AFB1 and OTA with red pepper produced in Hungary. This case calls attention to the importance of consistently screening imported batches of ground red pepper for aflatoxin and ochratoxin A content and strictly prohibiting the use of batches containing mycotoxin concentrations exceeding the maximum permitted level.  相似文献   

8.
Acrylamide in Asian foods in Hong Kong   总被引:3,自引:0,他引:3  
About 400 food samples, mainly Asian foods available in Hong Kong, were tested for acrylamide by an LC-MS/MS method using [1, 2, 3-13C3]-acrylamide as surrogate. The acrylamide levels in the more commonly consumed food items in the food groups such as rice and rice products, noodles, bakery and batter-based products, were generally less than 60 μg kg-1. Higher levels were found in the food groups such as biscuit-related products and crisps. The highest levels were detected in potato crisps (1500-1700 μg kg-1). Lower levels were found in rye flour-based crisps (440 μg kg-1), followed by corn-based (65 to 230 μg kg-1) and wheat flour-based crisps (61-200 μg kg-1), and then rice flour-based crisps (15-42 μg kg-1). The acrylamide formation during deep frying of a wheat flour-based product, Chinese fried fritter, was studied. Deep-frying at 170°C resulted in gentle but steady rise in acrylamide content. A steep rise for frying at 210°C was recorded. The moisture content of the product decreased with frying time, but the fat content increased. It is proposed that the reaction for the formation of acrylamide was initiated on the surface and then penetrated into the interior of the food matrix by heat transfer via radiation/conduction and diffusion of hot oil.  相似文献   

9.
In this study, microbiological tests for the detection of beta-lactam antibiotics in meat and meat products were evaluated. The traditional FPT (four plate test, containing Bacillus subtilis and Kocuria rhizophila), BsDA (Bacillus stearothermophilus disc assay) and a newly developed microbiological test, Premi®Test (containing Bacillus stearothermophilus) were included in the study. The limit of detection (LOD) of the Premi®Test was compared with the LOD of the traditional methods. The detection limits of the tests were determined by using beta-lactam antibiotic standards dissolved in meat juice, as well as meat tissue obtained from laying hens after experimental administration of amoxicillin. Positive samples, based on inhibition of growth of the organism in the test, were confirmed by high performance liquid chromatography (HPLC). Growth inhibition in the traditional tests is visible as a clear zone on the plate, whereas for Premi®Test, this is based on the absence of a colour change of the test. The LODs of antibiotics tested were as follows: Penicillin G (PENG) 5 µg kg-1, amoxicillin (AMOX) 10 µg kg-1, ampicillin (AMP) 25 µg kg-1, oxacillin (OXA) 30 µg kg-1, and cloxacillin (CLOX) 30 µg kg-1 on the plate with Bacillus stearothermophilus. Beta-lactam antibiotics can be detected also on one plate seeded with Kocuria rhizophila, although the LODs are higher: PENG 10 µg kg-1, AMOX 25 µg kg-1, AMP 30 µg kg-1, OXA 50 µg kg-1, and CLOX 50 µg kg-1. Premi®Test was performed according to the Standard Operating Procedure intended for detection of beta-lactam antibiotics in poultry tissues with following LODs: PENG 4 µg kg-1, AMOX 5 µg kg-1, AMP 5 µg kg-1, OXA 40 µg kg-1, CLOX 50 µg kg-1. All tests are able to detect beta-lactam antibiotics such as penicillin G, ampicillin, amoxicillin, oxacillin and cloxacillin below the maximum residue level (MRL). However, the detection limits of the Premi®Test for PENG, AMOX and AMP were below the limits of BsDA and the plate containing Kocuria rhizophila.  相似文献   

10.
Polyethylene terephthalate (PET) is frequently used as a packaging material for beverage bottles, fruit and vegetable trays, and egg crates in Japan. Levels of formaldehyde (FA), acetaldehyde (AA) and PET oligomers in various PET food packaging were determined. PET samples were initially dissolved in trifluoroacetic acid with 2,4-dinitrophenylhydrazine to derivatize formaldehyde and acetaldehyde to their dinitrophenylhydrazones. The stable derivatives along with the oligomers were analysed using HPLC with ultraviolet light detection at 360 and 254 nm, respectively. The PET pellets contained 3.5-12.4 µg g-1 AA and 4.0-7.2 mg g-1 oligomers, while FA was below the determination limit. FA, AA and oligomer levels in Japanese bottles were 0.6-3.0 µg g-1, 8.4-25.7 µg g-1 and 5.0-8.7 mg g-1, ND-1.6 µg g-1, 5.0-13.1 µg g-1 and 4.9-8.2 mg g-1 in French and Italian bottles, and ND-1.2 µg g-1, 9.1-18.7 µg g-1 and 5.6-8.0 mg g-1 in US and Canadian bottles, respectively. Compared with European bottles, Japanese bottles contain higher FA and AA levels. In sheet-moulding products, their contents were determined as ND-1.1 µg g-1, 11.5-43.1 µg g-1 and 4.6-9.2 mg g-1, respectively. The results show that sheet-moulding products contain lower FA and higher AA in comparison with bottles. FA and AA are considered to be generated from PET during the heating process for moulding the pellets to bottles or sheet-moulding articles and de-aeration during the sheet-moulding process is effective in removing FA. In contrast, the level of the oligomers remains unchanged during the moulding process from pellets to bottles or sheet products.  相似文献   

11.
Liquid-crystalline co-polyesters (e.g. a random copolyester based on p-hydroxybenzoic acid (HBA) and 2-hydroxy-6-naphthoic acid (HNA) known as Vectra A950) offer good barrier properties, but for food-contact use require overall and specific migration testing. For Vectra A950 films, the highest overall migration level obtained was 2.3 mg kg-1 in olive oil (10 days at 40°C) well below the EC limit of 60 mg kg-1. The highest specific migration for p-hydroxybenzoic acid was 15.2 μg dm-2 in olive oil (2h at 175°C). For 2-hydroxy-6-naphthoic acid, the highest value obtained was 4.3 μg dm-2 in 10% ethanol (4h at 100°C), although it was not on the EC positive and cannot yet be used for food-contact materials. At conditions considered as severe, the estimated daily intake for p-hydroxybenzoic acid was calculated as 11.9 μg/person day-1 and for 2-hydroxy-6-naphthoic acid it was 5.3 μg/person day-1. The results exceed the threshold of regulation of 1.5 μg/person day-1.  相似文献   

12.
A generic methodology for the assessment of consumer exposure to substances migrating from packaging materials into foodstuffs during storage is presented. Consumer exposure at the level of individual households is derived from the probabilistic modeling of the contamination of all packed food product units (e.g. yogurt pot, milk bottle, etc.) consumed by a given household over 1 year. Exposure of a given population is estimated by gathering the exposure distributions of individual households to suitable weights (conveniently, household sizes). Calculations are made by combining (i) an efficient resolution of migration models and (ii) a methodology utilizing different sources of uncertainty and variability. The full procedure was applied to the assessment of consumer exposure to styrene from yogurt pots based on yearly purchase data of more than 5400 households in France (about 2 million yogurt pots) and an initial concentration c0 of styrene in yogurt pot walls, which is assumed to be normally distributed with an average value of 500 mg kg-1 and a standard deviation of 150 mg kg-1. Results are discussed regarding both sensitivity of the migration model to boundary conditions and household practices. By assuming a partition coefficient of 1 and a Biot number of 100, the estimated median household exposure to styrene ranged between 1 and 35 µg day-1 person-1 (5th and 95th percentiles) with a likely value of 12 µg day-1 person-1 (50th percentile). It was found that exposure does not vary independently with the average consumption rate and contact times. Thus, falsely assuming a uniform contact time equal to the sell-by-date for all yogurts overestimates significantly the daily exposure (5th and 95th percentiles of 2 and 110 µg day-1 person-1, respectively) since high consumers showed quicker turnover of stock.  相似文献   

13.
The aim of this study was to determine the levels of lead and cadmium in chicken, pork, beef, lamb and turkey samples (both meat and meat products), collected in the island of Tenerife (Spain). Lead and cadmium were measured by graphite furnace atomic absorption spectrometry (GFAAS). Mean concentrations of lead and cadmium were 6.94 and 1.68 µg kg-1 in chicken meat, 5.00 and 5.49 µg kg-1 in pork meat, 1.91 and 1.90 µg kg-1 in beef meat and 1.35 and 1.22 µg kg-1 in lamb meat samples, respectively. Lead was below the detection limit in turkey samples and mean cadmium concentration was 5.49 µg kg-1. Mean concentrations of lead and cadmium in chicken meat product samples were 3.16 and 4.15 µg kg-1, 4.89 and 6.50 µg kg-1 in pork meat product, 6.72 and 4.76 µg kg-1 in beef meat product and 9.12 and 5.98 µg kg-1 in turkey meat product samples, respectively. The percentage contribution of the two considered metals to provisional tolerable weekly intake (PTWI) was calculated for meat and meat products. Statistically significant differences were found for lead content in meats between the chicken and pork groups and the turkey and beef groups, whereas for cadmium concentrations in meats, significant differences were observed between the turkey and chicken, beef and lamb groups. In meat products, no clear differences were observed for lead and cadmium between the various groups.  相似文献   

14.
Australian survey of acrylamide in carbohydrate-based foods   总被引:2,自引:0,他引:2  
A method was developed and validated for the determination of acrylamide in carbohydrate-based foods. Solid-phase extraction employing a mixed-bed anion and cation exchange cartridge in series with a C18 extraction disk was used to clean-up water extracts of food samples before analysis by liquid chromatography coupled with tandem mass spectrometry detection. The limit of detection was calculated as approximately 25 μg kg-1 and the limit of reporting was 50 μg kg-1. The average method recovery for 84 samples from a range of matrices reporting was 99% with a relative standard deviation of 11.2%. A survey was conducted of 112 samples of carbohydrate-based foods composited from 547 products available in the Australian market. The analytical results were used in conjunction with Australian food consumption data derived from the 1995 National Nutrition Survey (NNS) to prepare preliminary dietary exposure estimates of Australians to acrylamide through only the food groups examined. Mean dietary exposure to acrylamide resulting from consumption of the foods tested, for Australians aged 2 years and above, was estimated as 22-29 µg day-1 (equivalent to 0.4-0.5 µg kg-1 bodyweight day-1) and between 73 and 80 µg day-1 (1.4 and 1.5 µg kg-1 bodyweight day-1) for 95th percentile consumers. Young children (2-6 years) consuming acrylamide-containing foods had a higher acrylamide exposure on a per kilogram bodyweight basis (mean 1.0-1.3 µg kg-1 bodyweight day-1). The estimated exposure of Australians to acrylamide is similar to that estimated for other countries.  相似文献   

15.
Three hundred and twenty samples from the 1999 UK harvest comprising wheat (201 samples), barley (106) and oats (13) were analysed for ochratoxin A and deoxynivalenol. A small number of organic samples was also obtained. Samples were collected from farms, central stores, mills, maltings and ports from across the UK from February to April 2000. Ochratoxin A and deoxynivalenol analysis was by affinity column clean up and high-performance liquid chromatography with fluorescence and ultraviolet light detection, respectively, with limits of detection of 0.2 and 20 μg kg-1. The survey found ochratoxin A at below 5 μg kg-1 in 97% of the samples indicating satisfactory storage conditions. The remaining 3% of the samples contained ochratoxin A at levels between 5.2 and 231 μg kg-1, but none of these samples was intended for human consumption. Deoxynivalenol was detected in 88% of all samples, with 83% below 100 μg kg-1; the maximum level was 600 μg kg-1. Twenty samples containing deoxynivalenol at or above 150 μg kg-1 by high-performance liquid chromatography were all confirmed by gas chromatography/mass spectrometry. Nivalenol was also detected by gas chromatography/mass spectrometry at levels of 50 μg kg-1 or higher in 18 of 20 samples where deoxynivalenol was confirmed.  相似文献   

16.
Bisphenol A-derived glycidyl ethers as well as its reaction products with other lacquer components can migrate into the packed food from epoxy-based can coatings. A sensitive and selective method is presented using high-performance liquid chromatography coupled with ultraviolet light, fluorescence and electrospray ionization-mass selective detection for the identification and quantification of all migrants with a bisphenol A backbone and a molecular weight below 1000 Da, an estimated boundary for the absorption in the gastrointestinal tract. The identification of migrants was confirmed by microreactions of technical bisphenol A diglycidyl ether with solvents and phenols, which provided the fragmentation pattern of the mass selective detection and relative retentions of 42 different bisphenol A-related substances. It was shown by calibration of different isolated and synthesized bisphenol A derivatives that the fluorescence response relies on the amount of bisphenol A moiety in the respective molecule. Therefore, all migrating bisphenol A-related substances below 1000 Da were determined as bisphenol A diglycidyl ether equivalents using a calibration (fluorescence detection) of the commercially available bisphenol A diglycidyl ether monomer. The limit of quantification was set at 5 μg bisphenol A diglycidyl ether equivalents kg-1 (or 0.8 μg dm-2). This method was validated for epoxy coatings (0.1 μg dm-2 limit of detection and 24 μg bisphenol A-related substances below 1000 Da dm-2 standard deviation, corresponding to 4.4% relative standard deviation). The quantification could be extended by combining the fluorescence response and structural information gained from the mass spectra, which provides more accurate results for each migrant. The calculation is based on the calibration of the bisphenol A chromophore content of the molecule. According to this method, the amount of migrating bisphenol A-related substances below 1000 Da in the acetonitrile extract (assuming a worst case) varied from about 0.4 to 0.7 mg dm-2 in the examined coatings. The determined amounts comply with about 50% of the total migrate below 1000 Da.  相似文献   

17.
The global problem of food products contaminated by residues of the banned carcinogenic nitrofuran drugs has prompted research into how such residues accumulate in tissues. In the study described here, two aspects have been investigated where the nitrofurans accumulate in tissues from chickens exposed to either a dietary or an environmental source of contamination. Twenty groups of broilers were fed a diet containing one of the nitrofurans: furazolidone, nitrofurazone, nitrofurantoin or furaltadone at concentrations of 30, 100, 300, 1000 and 3000 µg kg-1. At the lowest concentration of furazolidone contamination (0.01% of the therapeutic dose) tissue bound AOZ metabolite residues were detected in liver (1.1 ± 0.2 µg kg-1) and in muscle (0.33 ± 0.03 µg kg-1). Similar results were obtained for AMOZ (0.6 ± 0.2 µg kg-1 in liver), the tissue bound metabolite of furaltadone. There was no appreciable accumulation of nitrofurantoin in chicken muscle. The AHD metabolite was not detected in muscle from birds fed nitrofurantoin at either 30 or 100 µg kg-1. For nitrofurazone the concentrations of the SEM metabolite were higher in muscle than in liver for all dietary concentrations. The potential for a contaminated environment to cause nitrofuran residues in chickens was investigated. Six chickens were placed in a pen that was previously occupied by birds fed a diet containing 3000 µg kg-1 of furazolidone. After 24 hours' exposure of the chickens to the litter in the pen, AOZ residues of 0.13 ± 0.04 and 0.10 ± 0.03 µg kg-1 were detected in liver and muscle, respectively. The results of both experiments have implications for the poultry industry in trying to eliminate nitrofurans from their production systems, and for regulatory analysts faced with the detection of low concentrations of the drugs, both in tissues and in feedingstuffs.  相似文献   

18.
The results of surveillance for ochratoxin A (OTA) in 1885 samples of sultanas taken during five crop years between 1999 and 2003 are reported. The analytical method was based on extraction with methanol + sodium bicarbonate and clean-up by immunoaffinity column chromatography followed by high-performance liquid chromatography with fluorescence detection. The limit of detection for OTA was 0.3 µg kg-1. The results show that 9.3% of the samples contained no detectable levels of OTA, whereas 0.6% had concentrations exceeding 10 µg kg-1; the remaining 90.3% had levels within the range 0.3-10 µg kg-1. The overall mean OTA concentration in the total number of 1885 samples taken was 1.36 ± 2.91 µg kg-1; the overall median was calculated as 0.90 µg kg-1.  相似文献   

19.
There is no set protocol for completing refined exposure assessments of food-packaging migrants in the European Union. One novel method that could be used to provide more realistic exposure assessments and also reduce uncertainty in the exposure estimation could be the use of food consumption surveys that also have packaging information. The aim of the current study was to estimate exposure to two food-packaging migrants (expoxidized soybean oil (ESBO) and styrene monomer) using a food-consumption database that collected packaging information. The Irish National Children's Food Survey (NCFS) was completed in 2003-04 and it collected information on the type and amount of food consumed by 594 Irish children aged 5-12 years, in addition to the type of packaging used for these foods. The Irish Food Packaging Database (IFPD) was completed in parallel to this food consumption survey and recorded exact information on the contact layer used for the packaging. In a database that combined information from the NCFS and the IFPD, the packaging materials that could contain the target migrants were identified. If a food was packaged in a material that could contain the migrant, it was assumed that the migrant was present in the food. For the exposure assessment of ESBO the 90th percentile migration values of ESBO in foods derived from the literature were used. This was similar to a method as used by the European Food Safety Authority (EFSA) in their exposure assessment of ESBO for adults. Two scenarios of styrene exposure were undertaken in this study. In the first scenario the 90th percentile migration value for styrene found in foods was used; in the second scenario the maximum level of styrene found in foods was used. These migration values were derived from the literature. The mean intake of ESBO for Irish children was 0.023 mg kg-1 body weight day-1, which is well below the tolerable daily intake (TDI) of 1 mg kg-1 body weight day-1 set by the Scientific Committee for Food (SCF) in 1999. The food group that contributed most to ESBO intake was tomato sauces packed in glass jars with polyvinyl chloride (PVC)-lined metal lids (46.8%). For styrene, the mean intake was 0.122 µg kg-1 body weight day-1 when using the 90th percentile migration values and 0.169 µg kg-1 body weight day-1 when using the maximum migration values. These estimated intakes are below the provisional maximum tolerable daily intake (PMTDI) of 40 µg kg-1 body weight day-1, which was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1984. Therefore, the estimated intakes of the two migrants are not of concern for Irish Children and uncertainty is reduced in the assessment due to the fact that information is available on the type of foods consumed the type of packaging used for these foods.  相似文献   

20.
A rapid method was developed to allow the analysis of triazamate and the hydrolysis product triazamate acid in apples, peas and Brussels sprouts. The procedure was based on acidified methanol extraction with quantification by liquid chromatography coupled with tandem mass spectrometry detection. The detection limit, based on the lowest calibration level, was 0.005 mg kg-1. The method was validated at 0.05 and 0.01 mg kg-1, and was used for screening of triazamate acid in the surveillance of apples as part of the UK pesticide monitoring programme. Calibrations were linear over the range 0.004-0.080 µg ml-1 (equivalent to 0.005-0.11 mg kg-1), with a minimum correlation coefficient of 0.95. The detection response showed some matrix-dependent variation. Mean recoveries were in the range 70-108% with associated per cent coefficient of variations of less than 20%.  相似文献   

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