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1.
In this study, the co-occurrence of multiple mycotoxins in maize kernels collected from 300 households' stores in three agro-ecological zones in Tanzania was evaluated by using ultra high performance liquid chromatography/time-of-flight mass spectrometry (TOFMS) with a QuEChERS-based procedure as sample treatment. This method was validated for the analysis of the main eleven mycotoxins of health concern that can occur in maize: aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), ochratoxin A (OTA), deoxynivalenol (DON), fumonisin B1 (FB1), fumonisin B2 (FB2), HT-2 toxin, T-2 toxin and zearalenone (ZEN). From each zone one major maize producing district for home consumption was chosen and 20 villages for each district were randomly selected for sampling. All mycotoxins of health concern, except for T-2 toxin, were detected in the maize samples. Particularly high levels of AFB1 (50%; 3–1,081 μg kg−1), FB1 (73%; 16–18,184 μg kg−1), FB2 (48%; 178–38,217 μg kg−1) and DON (63%; 68–2,196 μg kg−1) were observed. Some samples exceeded the maximum limits set in Tanzania for aflatoxins or in European regulations for other mycotoxins in unprocessed maize. Eighty seven percent of samples were contaminated with more than one mycotoxin, with 45% of samples co-contaminated by carcinogenic mycotoxins, aflatoxins and fumonisins. Significant differences in contamination pattern were observed among the three agro-ecological zones. The high incidence and at high levels (for some) of these mycotoxins in maize may have serious implications on the health of the consumers since maize constitute the staple food of most Tanzanian population. Effective strategies targeting more than one mycotoxin are encouraged to reduce contamination of maize with mycotoxins.  相似文献   

2.
Fusarium head blight of wheat is caused by the Fusarium species that produces mycotoxins, such as deoxynivalenol (DON). The distribution of DON in wheat products can lead to high economic and health impacts. The objective of this study was to evaluate the natural distribution of DON in the wheat milling process and wheat-based products, as well as the daily intake estimates for the Southern Brazilian population. The fractions of wheat grains (milled wheat, finished flour and bran) were produced in a mill. Additionally, wheat-derived products, such as pasta, bread and crackers were analyzed. The bran fraction had the highest mean concentration of DON (2278 μg kg−1), followed by milled wheat and finished flour (1895 μg kg−1 and 1305 μg kg−1). The distribution factor in the finished flour (69%) fraction demonstrates that DON was reduced when compared to milled wheat, by contrast of bran fraction that presents higher DON levels (120%). A percentage of 35% bran, 35% finished flour and 30% milled wheat samples would not be in compliance with future Brazilian regulations for DON levels. From the wheat-based products analyzed, 17% of whole bread and 10% of salted cracker products were contaminated with DON, with a median of 437 μg kg−1 and 624 μg kg−1, respectively. The finished flour was the fraction that most contributes to the daily intake of DON in Southern Brazil, representing 89.6% of the provisional maximum tolerable daily intake.  相似文献   

3.
Mycotoxins are secondary metabolites produced by filamentous fungi that usually contaminate food products. Coffee is a natural product susceptible to mycotoxin contamination. The present study evaluates the presence of nivalenol, deoxynivalenol, T-2 and HT-2 Toxin, diacetoxyscirpenol, aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, fumonisin B1, fumonisin B2, ochratoxin A, zearalenone, enniatin A, enniatin A1, enniatin B, enniatin B1, and beauvericin in coffee samples, using liquid chromatography tandem mass spectrometry (LC-MS/MS). The results show that zearalenone was not present in any sample. In the positive samples the contents of fumonisins ranged from 58.62 to 537.45 μg/kg, emerging mycotoxins ranged from 0.10 to 3569.92 μg/kg, aflatoxins ranged from 0.25 to 13.12 μg/kg, and trichothecenes, excepting nivalenol, ranged from 5.70 to 325.68 μg/kg. Nivalenol presented the highest concentrations, from 0.40 to 25.86 mg/kg. Ochratoxin A ranged from 1.56 to 32.40 μg/kg, and five samples exceeded the maximum limit established by the European Commission.  相似文献   

4.
《Food Control》2014,36(1):117-122
A total of 76 cereal and oil products collected from Yangtze Delta region of China were analyzed for occurrences of aflatoxins (AFs), aflatoxin B1 (AFB1), ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZEN). The mycotoxins were determined by the standard detection procedures using immunoaffinity column clean-up coupled with fluorometer (or HPLC-UV). ZEN was the most prevalent toxin, with the incidence of 27.6% (range = 10.0–440.0 μg kg−1), and 9.2% of the evaluated samples were contaminated with a concentration higher than that of the legislation limit of China (60 μg kg−1). AFs and AFB1 were detected in 14.5% of the samples analyzed, the concentrations ranging 1.1–35.0 μg kg−1 for AFs, and 1.0–32.2 μg kg−1 for AFB1; 4.0% of the samples had the concentrations of AFs and AFB1 higher than that of the corresponding legislation limits of China (5.0, 10.0 and 20.0 μg kg−1 for different products). OTA was detected in 14.5% of the cereal and oil products collected; the concentrations ranged 0.51–16.2 μg kg−1. Only 2 samples showed OTA levels higher than that of the legislation limit of China (5.0 μg kg−1). DON was detected in 7.9% of the samples; the concentrations ranged 100–700 μg kg−1, and none of the samples showed DON concentration higher than that of the legislation limit of China (1.0 mg kg−1). A total of 15.8% cereal and oil products were contaminated with at least two mycotoxins (multiple contaminations with different combinations including AFs-ZEN, AFs-OTA-ZEN, OTA-ZEN, ZEN-DON, OTA-ZEN-DON). The dietary exposure assessment results indicated that AFs (AFB1), OTA, DON and ZEN from cereal-based products represented a series health risk to both adults and children in Yangtze Delta region of China. This is the first report of safety evaluation associated with major mycotoxins for the area.  相似文献   

5.
The natural occurrence of mycotoxins in maize in Argentina, from 1999 to 2010 was analysed. Total aflatoxins, deoxynivalenol and zearalenone, were detected and quantified by TLC. Each aflatoxins and fumonisins was quantified by HPLC. A total of 3246 samples for freshly harvested (1655) and storage (1591) was obtained from different regions, from 1999 to 2010. Except for 2003 year in harvest, and for 2007 in storage, aflatoxins levels were low. Average values of aflatoxin B1 for freshly harvested samples were between 0.38 and 2.54 μg kg−1 and for storage samples were between 0.22 and 4.5 μg kg−1. The average values and frequency of contamination for zearalenone and deoxynivalenol, were low for all years. The average zearalenone contamination in samples of freshly harvested, showed values from no detected up to 83 μg kg−1, and in storage samples, from no detected to 17 μg kg−1. The average deoxynivalenol contamination of freshly harvested, showed values from no detected up to 140 μg kg−1, and for storage samples showed values from no detected to 14 μg kg−1. The percentage of maize samples contaminated by fumonisins was between 90 and 100% for all years studied; the average levels were from 1773 to 9093 μg kg−1 for freshly harvested maize and for storage from 2525 to 11,528 μg kg−1.Co-occurrence of aflatoxins and fumonisin was the most frequent (8.4%), followed by zearalenone and fumonisins (2%).  相似文献   

6.
In this study, we aim to determine co-occurrence of aflatoxins (AFs) and ochratoxin A (OTA) in cereal flours commercialised in Corum, Turkey. One hundred cereal flours were checked for target fungal metabolites between the years 2011 and 2013. The samples were analysed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) after immunoaffinity column (IAC) clean-up procedure. The method was successfully validated in accordance to European Union guidelines acceptance criteria for specificity, linearity, sensitivity, trueness and repeatability. All the results are well below the maximum limits specified in the EU legislation. AFs were detected neither wheat flour nor rice flour samples, while 66.7% of maize flours contained AFs with maximum concentration of 1.12 μg kg−1. OTA was present in 26.7% of wheat flour, 41.7% of maize flour and 18.8% of rice flour samples, with mean levels of 0.247, 0.218 and 0.154 μg kg−1, respectively. The co-occurence of AFs and OTA was found in 9 maize flour samples.  相似文献   

7.
A multi-mycotoxin analysis method based on liquid chromatography coupled to triple quadrupole mass spectrometry was validated and applied for the determination of twenty-six mycotoxins, including eight trichothecenes, three fumonisins, sterigmatocystin, ochratoxin A, four aflatoxins, zearalenone, five “emerging” mycotoxins and three Alternaria mycotoxins in 74 durum wheat samples from central Italy. Eighty-eight percent of the analysed samples contained one or more mycotoxins, with enniatin B showing the highest contamination levels (78% of samples with levels ranging from 23 to 1826 ng/g), followed by enniatin B1 (10–1384 ng/g) and deoxynivalenol (48–2267 ng/g). This work gives an important contribution in terms of mycotoxin analysis and occurrence in durum wheat and in assessing the mycotoxicological risk posed by both traditional and emerging mycotoxins for the final consumers of durum wheat derived products.  相似文献   

8.
A fast and simple method was developed to determine pyrrolizidine alkaloids (PAs) in honey using liquid chromatography tandem mass spectrometry (LC- MS/MS) with electrospray ionization (ESI). An efficient extraction procedure was carried out by simply diluting with water, without the need of any additional clean-up steps. A full validation of the method was performed according to Commission Decision 2002/657/EC. The method was linear in the 050 μg kg−1 range and presented satisfactory intra-day and inter-day precision with relative standard deviations of 1.45–10.2% and 1.60–1–0.2%, respectively. The measurement uncertainty, limit of detection (LOD) (0.1–1.0 μg kg−1) and limit of quantification (LOQ) (0.2–1.5 μg kg−1) were also calculated. The proposed method was applied to analyse eight PAs, namely, senecionine, senecionine-N-oxide, echimidine, intermedine, lycopsamine, retrorsine, monocrotaline and retrorsine-N-oxide, in 92 commercial honey samples from Brazil. At least three PAs were detected in 99.1% of the samples. PAs were not detectable (<LOD) in only one sample. Because PAs are natural toxins biosynthesized by plants, the importance of monitoring their concentration in honey is evident. For this purpose, a simple, low-cost extraction procedure was performed, and a high-throughput method was developed.  相似文献   

9.
《Food Control》2014,35(2):268-273
A method consisting of solvent extraction using hexane for defatting, multifunctional cleanup column, and HPLC determination was validated for the analysis of deoxynivalenol (DON) and zearalenone (ZEA) in wheat germ and wheat germ oil. A total of 36 batches of grain wheat were subjected to industrial milling and the distribution factors in milled germ were 47% for DON and 71% for ZEA. A survey of 50 samples of germ-based dietary supplements revealed that 60% of wheat germ and 40% of wheat germ oils contained DON at mean values of 111 and 41 μg/kg, respectively, while none of germ samples and 16% oils contained ZEA (mean 6 μg/kg). Contamination levels lead to a daily intake of 1.3 μg DON and 0.03 μg ZEA, representing 1.9% and 0.23% of their respective tolerable daily intakes (TDI).  相似文献   

10.
A membrane-based flow-through immunoassay for rapid non-instrumental multi-detection of ochratoxin A (OTA), zearalenone (ZEN) and fumonisin B1 (FB1) in cereal grains and silage was developed. The test is based on a direct competitive enzyme immunoassay performed on a membrane. Alkaline phosphatase was used as enzyme label to decrease matrix interference. The analytical method involved a fast extraction procedure (extraction with a mixture of methanol, water and acetic acid 79:20:1, v/v) followed by a multi-detection. The immunotest allows the visual estimation of the presence of three mycotoxins in less than 15 min. The cut-off limit of this test have been set at a value not higher than half of EU legislative limits (2.5, 50 and 1000 μg kg−1 for OTA, ZEN and FB1 correspondingly in wheat; 2.5, 100 and 1000 μg kg−1 in maize; 25, 125 and 2500 μg kg−1 in silage). Evaluation and validation studies have been performed using spiked and naturally contaminated samples and results were compared with LC–MS/MS. Also the possibility of analyte detection in wheat at two concentration levels by the immunotest was demonstrated with OTA and ZEN as an example. In spite of the semiquantitative-qualitative character of the test, the results demonstrate that the test provides a very good estimation of the mycotoxins concentration in wheat, maize and silage. This test format could be adapted to the multi-detection of other contaminants in food and feed.  相似文献   

11.
In this study, 50 dried eggplant and 50 dried green bell pepper samples were analyzed in terms of their aflatoxin and ochratoxin A (OTA) content. Aflatoxins G2, G1, B2, and B1, and OTA contents were analyzed using high-performance liquid chromatography with a flame ionization detector (HPLC–FID). Total aflatoxin and, as well as aflatoxin G2, G1, B2, and B1 content in dried eggplant samples were ranged between 0.82 and 2.58, 0.10–0.23, 0.32–1.35, 0.12–0.67, and 0.17–0.71 μg kg−1, respectively. Total aflatoxin and, as well as aflatoxin G2, G1, B2 and B1 content in dried green bell pepper samples were 0.81–2.42, 0.11–0.22, 0.32–1.38, 0.13–0.66, and 0.18–0.91 μg kg−1, respectively. OTA content was varied from 8.88 to 21.35 μg kg−1 in eggplant samples, and from 15.38 to 24.70 μg kg−1 in dried green bell pepper samples. Of the dried eggplant samples and dried green bell pepper samples, 36% and 24% of them, respectively, had aflatoxin B1 values which were below the minimum limit of detection (LOD) of 0.05 μg kg−1. None of the analyzed samples exceeded the legal limit values of 10 μg kg−1 for total aflatoxin content, and 5 μg kg−1 for aflatoxin B1 content. However, 80% of the dried eggplant samples and 100% of the dried green bell pepper samples exceeded the legal limit value for OTA content (15 μg kg−1). According to the results, it was concluded that dried vegetables should be examined in terms of their aflatoxins. It is essential to analyze OTA content more thoroughly, as it has the potential to pose a risk for public health, as well as for the economy.  相似文献   

12.
Corn infected with Ustilago maydis, causal agent of common smut disease, produces galls that are used as food in certain cultures, but may be contaminated with mycotoxins. The objective of this study was to determine mycotoxin levels in common smut galls (CSGs) collected from the field at corn ear reproductive stages R1 through R5 and in commercial CSGs products. The study was conducted in 2012 and 2013. A simple extraction method for five mycotoxins was devised and the results showed the presence of these compounds in CSGs in corn during ear development at various physiological stages. Fumonisin was the major mycotoxin in CSG samples in both 2012 (63%, ≤150.7 μg g−1) and 2013 (46.9%, ≤20.9 μg g−1); followed by aflatoxin (2012: 2%, ≤14.7 ng g−1; 2013: 30.6%, ≤10.8 ng g−1) and zearalenone (2012: ≤41.70 ng g−1; 2013: ≤12.40 ng g−1). Deoxynivalenol (DON) was only detected in 2012 (≤1.6 μg g−1), and cyclopiazonic acid was only detected in 2013 (≤3.18 μg g−1). Commercial canned and fresh CSG samples also contained detectable amounts of mycotoxins including aflatoxin, fumonisin, CPA, and DON. Aspergillus flavus was isolated from selected 2013 CSG field samples at R2 or older (0–1.6 × 106 cfu/g), whereas Fusarium spp were isolated at R1 or older (0–7.5 × 107 cfu/g). These results indicate that CSGs can be infected with mycotoxigenic fungi and contaminated with mycotoxins. The incidence of mycotoxins in commercially available CSG products was highly variable and warrants further study.  相似文献   

13.
A methodology has been developed to identify and quantify 257 toxic substances (including pesticides and mycotoxins) in diverse isoflavones supplements obtained from soy. Two different extraction procedures were compared, QuEChERS and “dilute and shoot”. The best results were observed when the “dilute and shoot” methodology was applied using acetonitrile acidified with formic acid (1% v/v) as extraction solvent followed by a clean-up step with Florisil cartridges. Validation of the method was carried out evaluating trueness, repeatability and intermediate precision, obtaining recoveries between 70 and 120% with relative standard deviation (RSD) values lower than 20%. Limits of detection and quantification were below 5 and 10 μg kg−1 respectively. The validated methodology was applied to the analysis of real samples, finding pesticides such as flutolanil (12.2 μg kg−1) and etofenprox (48.2 μg kg−1). Regarding mycotoxins, aflatoxin B1 (8.2–17.1 μg kg−1) and aflatoxin G2 (6.4 μg kg−1) were detected.  相似文献   

14.
The natural occurrence of fumonisin B1 (FB1) and its co-occurrence with zearalenone (ZEA), T-2 toxin and deoxynivalenol (DON) were surveyed in 103 winter wheat samples collected after four to six-month storage in family barns from different locations in Serbia. All 103 samples were mycotoxin positive. The mean concentrations of all mycotoxins except ZEA were greater in 2005 than in 2007. FB1 was detected in 82.1% and 92.0% of all samples with ranges of 750-5400 μg kg−1 (mean, 2079.45 μg kg−1) and 750-4900 μg kg−1 (mean 918.76 μg kg−1) in 2005 and 2007, respectively. Moderate positive correlations were found between FB1 and DON concentrations (r = 0.56 in 2005 and r = 0.54 in 2007) and between FB1 and ZEA concentrations (r = 0.48 in 2005 and r = 0.60 in 2007), while a moderate negative correlation was detected between the production of FB1 and T-2 toxin in 2007 (r = −0.33). This is the first report of FB1 occurrence in naturally-contaminated wheat grain and its simultaneous occurrence with ZEA, DON and T-2 toxin in Serbia. Moreover, this is one of the rare reports presenting the occurrence of FB1 on wheat in the world.  相似文献   

15.
This study aims to assess the risk of aflatoxins (AFs) in traditional confectionery products (walnut sujuk and Turkish delight) of Turkey. A high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method was used for the determination of AFs. Evaluation of the method showed good selectivity, linearity, recovery and precision. The limit of quantification (LOQ) ranged from 0.106 to 0.374 μg kg−1. The expanded measurement uncertainty was less than 40% for all target analytes. The validated method was successfully applied to the determination of AFs in 112 traditional confectionery products containing nuts (hazelnuts and walnuts). AFs were detected in 43.8% of walnuts and 60.9% of hazelnuts used as ingredients in walnut sujuk and Turkish delight and at levels ranging from 0.58 to 15.2 μg kg−1 and 0.43–63.4 μg kg−1, respectively. This means that AFs levels in walnut sujuk and Turkish delight were up to levels of 6.1 and 9.5 μg kg−1, respectively. Six walnut samples and twenty-one hazelnut samples were above the EU maximum limits (MLs) of 2 and 5 μg kg−1 for aflatoxin B1 (AFB1), respectively.  相似文献   

16.
Heavy metals can be accumulated by marine organisms thought a variety of pathways, including respiration, adsorption and ingestion. The levels of heavy metals are known to increase drastically in marine environment through mainly anthropogenic activities. Fish are good indicators for the long term monitoring of metal accumulation in the marine environment. The aim of this study was to determine the levels of Cd, As, Hg, Pb, Zn and Cu in edible part and gill of seven most consumed Bulgarian fish species collected from north-east coast of Black Sea. These fish species are sprat (Sprattus sprattus sulinus), Mediterranean horse mackerel (Trachurus mediterraneus ponticus), Black sea gobies (Neogobius melanostromus), shad (Alosa pontica), Atlantic bonito (Sarda sarda), bluefish (Pomatomus saltatrix) and grey mullet (Mugil cephalus). The fish samples were collected during 2010. The analytical determination of As, Cd, Pb, Zn and Cu were performed by using flame and graphite furnace atomic absorption spectrometry after microwave digestion procedure. The total mercury determination was determined using a direct mercury analyzer (DMA-80). The metal concentration of analyzed elements was highest in the gill for all fish species. The maximum metal concentration was measured for Cu (1.40 mg kg−1 w.w), Zn (11 mg kg−1 w.w) and Pb (0.08 mg kg−1 w.w) in muscle tissues of shad and sprat. The edible part of horse mackerel has the maximum value for Hg (0.12 mg kg−1 w.w) while Atlantic bonito predominantly accumulates As (1.10 mg kg−1 w.w). The analytical results obtained from this study were compared within acceptable limits for human consumption set by various health institutions.  相似文献   

17.
Fumonisin B1 was investigated in samples of rice intended for human consumption, including polished parboiled rice, whole grain rice and whole grain parboiled rice. Until the present, no studies on the occurrence of fumonisin B1 have been performed on these types of rice that are commercially available in the south-eastern region of Brazil. A careful intralaboratory validation was carried out to demonstrate the fitness-of-purpose of the applied method for determining fumonisin B1 in the three studied rice types. The performance criteria – selectivity, reliable limits of detection (50 μg kg−1) and quantification (100 μg kg−1), linearity (range 100–2500 μg kg−1), precision (RSD values ≤ 17.0%) and recovery (71.7–112.0 %) were evaluated, and the expanded measurement uncertainty was estimated by using the data obtained from precision and recovery experiments. Matrix-matched calibration standards were employed to quantify the mycotoxin levels in the rice samples, in which the residual normality, homoscedasticity and independence were confirmed. In addition, the measurement uncertainty values are consistent with the maximum acceptable uncertainty established by European Union regulation for analytical methods for controlling mycotoxins in foodstuffs. Among the thirty-one commercial samples of rice analysed in the present study, five samples presented detectable levels of the mycotoxin, and these levels ranged from 64.8 to 163.0 μg kg−1.  相似文献   

18.
The objectives of this study were to assess aflatoxin M1 (AFM1) contamination in bulk tank milk, and to further identify the risk factors associated with the presence of AFM1 in raw milk in Argentina. The presence of AFM1 was investigated in 160 bulk tank milk samples collected from farms located in the most important milk production region in Argentina during one year (four seasons). Samples were analysed using immunoaffinity column (IAC) cleanup and UHPLC-MS/MS method for determining AFM1 at low levels of concentrations (LOQ = 0.003 μg L−1). A survey about the potential factors associated with the presence of AFM1 in milk was performed directly in the field through a questionnaire applied to the farmers. Chi-square and logistic regression were performed with presence of AFM1 in milk as dependent variable, and potential risk factors as independent variables. Incidence of AFM1 in raw milk was 38.8% and, in all samples, AFM1 levels were lower than the Southern Common Market (MERCOSUR) Regulation (maximum level accepted = 0.5 μg L−1). Commercial feed consumption (OR = 4.630, P = 0.001), soybean expeller consumption (>0.95 kgDM/cow) (OR = 3.542, P = 0.019), and cotton seed consumption (>1.5 kgDM/cow) (OR = 2.949, P = 0.089) were associated with the incidence of AFM1 in raw milk. Despite the incidence and the level of AFM1 in milk produced and commercialized in Argentina is not a serious problem for public health. The farm breeding intensification and the supplementation with commercial feed, soybean expeller, and cotton seed seems to be the risk factors that impacts on the AFM1 milk contamination. Therefore, Argentina should improve its monitoring program on mycotoxins in animal feed and milk and improve the management practices in farms.  相似文献   

19.
《Food Control》2010,21(8):1099-1103
This study was undertaken to determine the presence of mycotoxins in foods from Jordan. For this purpose, a total of 108 samples of different groups of foods widely consumed by the Jordanian population were collected during 2008–2009 years. Samples were analyzed for contamination with aflatoxins, ochratoxin A, deoxynivalenol, fumonisins, zearalenone and T-2 toxin by direct competitive enzyme-linked immunosorbent assay (ELISA). The predominant mycotoxin was ochratoxin A with a mean level of 4.17 μg kg−1 in 25% of analyzed samples. Furthermore, aflatoxins, deoxynivalenol and fumonisins were detected with a contamination frequency of 3%, 4% and 2%, respectively. The present report is the first one ever carried out on the occurrence of mycotoxins in food consumed by the Jordanian population.  相似文献   

20.
The use of corticosteroids and anabolic steroids in food producing animals is regulated or banned in the European Union (EU). However, their use as growth promoters cannot be excluded. Milk replacers, considered by EU legislation as feeds, may be a good way of administration of these compounds. In order to improve the control of growth promoter utilization in animal husbandry and preventing possible consequences to animal welfare, we developed a method for multiresidue analysis of prednisolone, prednisone, dexamethasone, cortisone, cortisol, 17α- and 17β-boldenone and their precursor androstadienedione (ADD), testosterone, epitestosterone, 17α- and 17β-nandrolone, and trenbolone in powdered milk for calves. All analytes were extracted, after a common deproteinization and defatting sample pre-treatment, by a unique immunoaffinity column and analysed by liquid chromatography tandem mass spectrometry (LC–MS/MS) in both positive and negative electrospray ionization (ESI) modes. The method was validated according to the criteria of the Commission Decision 2002/657/CE. The analytical limits were from 0.39 to 0.73 ng mL−1 for the decision limit (CCα) and 0.46–0.99 ng mL−1 for detection capability (CCβ). The analysis of 50 samples of milk replacers for calves, always revealed the presence of cortisol and cortisone (average concentrations 2.56 and 1.06 ng mL−1, respectively), frequently testosterone and epitestosterone (1.24 and 0.63 ng mL−1, respectively), occasionally β-nandrolone (0.82 ng mL−1) and prednisolone (0.41 ng mL−1). The other anabolic steroids were never found.  相似文献   

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