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1.
Occurrence of alternariol, alternariol monomethyl ether and tenuazonic acid in Argentinean tomato puree 总被引:1,自引:0,他引:1
The occurrence ofAlternaria mycotoxins was investigated in 80 samples of tomato puree processed and sold in Argentina. Alternariol (AOH), alternariol
monomethyl ether (AME) and tenuazonic acid (TA) were searched for by liquid chromatography. Thirty-nine of the 80 samples
showed mycotoxin contamination. TA was found in 23 samples (39-4021 μg/kg), AOH in 5 samples (187-8756 μg/kg), and AME in
21 samples (84-1734 μg/kg). Co-occurrence of two of these toxins was detected in 10 samples. This is the first report of natural
occurrence of AOH, AME and TA in tomato products in Argentina. 相似文献
2.
A total of 92 samples — 23 winter wheat, 12 summer barley, 5 oats and 52 mixed feed — were collected from a state factory
in Kaunas, Lithuania and were analysed for the presence of trichothecenes, zearalenone (ZEN) and ochratoxin A (OA) using gas
chromatography with electron capture detection and immunoaffinity column/high performance liquid chromatography with fluorescence
and UV detections. Deoxynivalenol (DON), nivalenol (NIV), T-2 toxin and HT-2 toxin were detected at concentrations above 10
μg/kg in 68%, 48%, 38% and 8% of cereal samples, respectively, and in 98%, 88%, 12% and 8% of samples of mixed feed for swine
and poultry. More than 10 μg/kg of zearalenone and ochratoxin A were found in 58% and 92% of the mixed feed samples, respectively.
The highest concentrations of all analysed trichothecenes in Lithuanian mixed feed and cereal grains, with an exception of
T-2 toxin in one oat lot and one sample of mixed feed and OA in two mixed feed samples, were lower than those reported as
Lithuanian advisory or tolerance limits. 相似文献
3.
Determination of ochratoxin A in urine and faeces of swine by high-performance liquid chromatography
Hana Valenta Imke Kühn Klaus Rohr 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1993,613(2)
Sensitive methods for the determination of ochratoxin A in urine and faeces of swine are described. The samples were extracted with chloroform at pH <2, and the extracts were cleaned up by a combination of solid-phase extraction and liquid—liquid partition. High-performance liquid chromatography with fluorescence detection was used for detection and determination. The detection limits were 0.3 ng/ml for urine and 1.5 ng/g for faeces. Recoveries of ochratoxin A from spiked samples of urine and faeces were 93% and 60%, respectively. Because of the low detection limit and the fast and relatively easy performance, the method for the determination of ochratoxin A in urine proved suitable for the estimation of possible contamination of live animals. 相似文献
4.
An ultra performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS) method was developed for the determination
of the Alternaria toxins tenuazonic acid, alternariol, alternariol monomethyl ether, altenuene, altertoxin I and tentoxin. Owing to its instability,
altenusin could not be determined. The sample preparation includes an acidic acetonitrile/water/methanol extraction, followed
by SPE clean-up step, before injection into the UPLC-MS/MS system. The separation was made on an Acquity UPLC column using
a water/acetonitrile gradient with ammonium hydrogen carbonate as a modifier. Matrix compounds of real samples led to enhancement
as well as suppression of the target compounds, depending on analyte and matrix. The recoveries were between 58 and 109% at
a level of 10 μg/kg. Eighty-five tomato products, consisting of peeled and minced tomatoes, soup and sauces, tomato purées
and concentrates, ketchup as well as dried and fresh tomatoes, were taken from the Swiss market in 2010. Tenuazonic acid was
found most frequently (81 out of 85 samples) and in the highest levels of up to 790 μg/kg. Alternariol and alternariol monomethyl
ether were found in lower concentrations, ranging from <1 to 33 μg/kg for alternariol and <5 to 9 μg/kg for alternariol monomethyl
ether. Only a few samples were positive for altenuene and tentoxin. Altertoxin I was never detected. 相似文献
5.
A method was validated for the determination of ochratoxin A (OTA) in soluble and green coffee. Performance parameters evaluated
included selectivity, accuracy, intermediate precision, linearity, limit of detection, limit of quantitation, and ruggedness.
The method was found to be selective for OTA in both matrices tested. Recovery rates from soluble coffee samples ranged from
73.5 to 91.2%, and from green coffee samples from 68.7 to 84.5%. The intermediate precision (RSDr) was between 9.1 and 9.4%
for soluble coffee and between 14.3 and 15.5% for green coffee analysis. The linearity of the standard calibration curve (r2) was <0.999 for OTA levels of 1.0–20.0 μg/kg in coffee samples. The limit of detection was determined to be 0.01 ng of OTA
on column, while the limit of quantitation was found to be 0.03 ng on column. The limit of quantitation is equivalent to 0.6
μg/kg in soluble coffee samples and 0.3 μg/kg in green coffee samples. The results of the ruggedness trial showed two factors
are critical for soluble coffee analysis: the extraction method, and the flow rate of the mobile phase. For green coffee analysis
two critical factors detected were the extraction method and the storage temperature of the immunoaffinity column.
Five samples of soluble coffee and 42 of green coffee were analysed using the validated method. All soluble coffee samples
contained OTA at levels that ranged from 8.4 to 13.9 μg/kg. Six of the 42 green coffee samples analysed (14.3%) contained
OTA at levels ranging from 0.9 to 19.4 μg/kg. The validated method can be used to monitor OTA levels in Colombian coffee for
export or for local consumption. 相似文献
6.
Simultaneous analysis of beauvericin and moniliformin in fungal cultures and in cereal grain samples
Species ofFusarium subglutinans andFusarium proliferation have been found to produce two mycotoxins, beauvericin and moniliformin, under labolatory conditions as well as in infected
ears. A method for simultaneous extraction, analysis and quantitation of both metabolites was elaborated. Recoveries were
85–97 % and 78–94 % for the first and the latter mycotoxin, respectively. Detection limit of beauvericin on high- performance
thin- layer chromatography plates (Merck 5633) after exposure to iodine vapours was 3 μg/g and by high- performance liquid
chromatography method 0.07 μg/g while moniliformin was analyzed at concentration level 1 μg/g by thin- layer chromatography
and 0.05 μg/g by high- performance liquid chromatography method. 相似文献
7.
Forty-seven samples of corn were collected from various street bazaars and market outlets in different regions of Turkey and
total aflatoxin (AF) and ochratoxin A (OTA) levels were determined by enzyme-linked immunosorbent assay (ELISA) following
sample preparation. Levels of AF and OTA in corn samples ranged between 1.75–120.3 μg/kg and 1.08–8.57 μg/kg, respectively.
Although 53% of the samples analysed had no detectable levels of AF, 4% of similar samples were found to contain AFs above
the acceptable limit of 10 μg/kg in Turkey. For OTA, 4% of the corn samples had levels above the acceptable limit (3 μg/kg)
in Turkey, with over 43% samples not found to contain this mycotoxin. Although the levels of mycotoxins analysed in this study
were not found to be high and the percentage of samples contaminated above permitted limits were low, the importance of overall
daily dietary intake should not be underestimated and control of these fungal metabolites in corn must be explored to minimise
the hazards they may cause in humans. 相似文献
8.
G. P. Kononenko A. A. Burkin E. V. Zotova N. A. Soboleva 《Applied Biochemistry and Microbiology》2000,36(2):177-180
Ochratoxin A was quantitatively monitored in grain extracts by indirect solid-phase enzyme immunoassay with the use of an
immobilized conjugate of the toxin with gelatin and polyclonal rabbit antibodies raised against the ochratoxin A-BSA conjugate.
This monitoring found that 1.7 to 18.5% of the samples were contaminated with the toxin at a concentration of 25.9–291.7 μg/kg.
An analysis of forage grain found ochratoxin A at concentrations of 440-3250 μg/kg. 相似文献
9.
For some foodstuffs, determination of the mycotoxin ochratoxin A (OTA) requires time consuming clean up by means of solid
phase extraction (SPE). Therefore a system for automated SPE was tested for cleaning up roasted coffee as a possible way of
shortening preparation time. Validation of the method in accordance to the so called “Concept '98” led to a LOD of 0.2 μg/kg
and a recovery rate of 92%. By using the described procedure with samples of roasted coffee the OTA contents varied between
the LOD and 3.4 μg/kg. This method was also used to determine ochratoxin A in liquorice roots, ginger and valerian.
Presented at the 26th Mykotoxin Workshop in Herrsching, Germany, May 17–19, 2004 相似文献
10.
In this presentation, the mycotoxin levels—as analysed by the analytical centre for mycotoxin surveillance of the state food
laboratory (LAVES Braunschweig)—for approximately 500 food samples are reported. The samples were collected in the year 2009
at retail in the German federal state of Lower Saxony. Aflatoxin and ochratoxin A were analysed in dried fruits, spices, cereals
and tree nuts. Ochratoxin A was detected in all samples of dried vine fruits, at levels up to 8.1 μg/kg. Aflatoxins and ochratoxin
A were also found in nutmeg and curry powder: the maximum regulatory levels for aflatoxins were exceeded in 25% of the nutmeg
samples. Nearly all samples of basmati rice contained aflatoxins, although at levels below the maximum regulatory level in
all but one sample. Aflatoxins were also detected in about 50% of hazelnut samples, in 20% of the samples the maximum levels
was exceeded (maximum 23.2 μg/kg). In contrast, aflatoxin contents in pistachios were surprisingly low. Fusarium toxins were
analysed in cereals and cereal products such as flour, bread, and pasta. Deoxynivalenol (DON) was the predominant toxin found
in these samples: DON was found in about 40% of the samples, although the maximum levels were not exceeded (max. 418 μg/kg).
Fumonisins (FBs) and zearalenone (ZEA) were specifically analysed in maize products (snacks, flour and oil). Most of these
samples (80%) were positive, but at levels not exceeding the maximum levels. Maximum levels were 98 μg/kg (ZEA) and 577 μg/kg
(sum of FB1 and FB2). Ergot alkaloids (six major alkaloids) were analysed in rye flour, and approximately 50% were positive. The highest concentration
of ergot alkaloids was 1,063 μg/kg; the predominant alkaloids were ergotamine and ergocristine. In conclusion, the results
indicate that continuous and efficient control measures for mycotoxins in a wide range of critical foods are necessary to
ensure compliance with maximum levels. Although the mycotoxin levels in the vast majority of samples were below maximum levels,
year-to-year variation and changes in the production of relevant commodities may result in a different picture in the future. 相似文献
11.
The commercially available dog food samples (29 dry foods and 11 wet foods) were analysed for deoxynivalenol (DON) and ochratoxin
A (OTA) using ELISA. All (100%) dry foods were contaminated with DON with various amount of the toxin (22-1837 μg/kg). In
wet food 3 samples were found to be positive for DON in the range of 95-170 μg/kg. There were a few samples contaminated with
OTA: 3 samples in dry foods (7-40 μg/kg) and 2 samples in wet foods (45 and 115 μg/kg). 相似文献
12.
Hee-Mock Oh Seog June Lee Jee-Hwan Kim Chan-Sun Park Byung-Dae Yoon 《Biotechnology and Bioprocess Engineering》2000,5(6):418-421
A new direct colorimetric assay of microcystin in water and algal samples is proposed consisting of two procedures as follows:
1) the elimination of phosphorus in the sample and concentration of microcystin using a C18 cartridge, 2) the detection of the released phosphorus by the ascorbic acid method and determination of protein phosphatase
(PP) inhibition by microcystin. The optimum amounts of phosphorylase α and PP-1 in 50 μL concentrated sample were 50 μg/50
μL buffer and 1.0 unit/50 μL buffer, respectively, for the best assay. The pH for the maximum activity of PP-1 was 8. The
minimum detectable concentration for this method was about 0.02 μg/L, which is sufficient to meet the proposed guideline level
of 1 μg microcystin/L in drinking water. Consequently, it would seem that the proposed direct colorimetric assay using PP
is a rapid, easy, and convenient method for the detection of microcystin in water and algal samples. 相似文献
13.
Corn samples were collected in 1999 from three departments of Entre Réos province, Argentina, and were surveyed for mould
contamination and natural occurrence ofFusarium mycotoxins, ochratoxin A and aflatoxins.Fusarium verticillioides was the most prevalent fungal species recorded at all departments. Zearalenone, deoxynivalenol and ochratoxin A were not
found in any samples. Only one of the 52 corn samples analysed was contaminated with aflatoxin B1 (17 μg/kg). Fumonisin B1 was found in 58 % of samples (range of positive samples: 47– 3,347 μg/kg), fumonisin B2 in 33.0 % (range of positive samples: 23–537 μg/kg) and fumonisin B3 in 25.0 % (range of positive samples: 24–287 μg/kg) of them. This is the first report on the natural occurrence of mycotoxins
in corn from Entre Ríos province, Argentina. Levels of fumonisins were lower than detected in other Argentinian provinces. 相似文献
14.
Natural Occurrence of Mycotoxins in Staple Cereals from Ethiopia 总被引:1,自引:0,他引:1
The occurrence of mycotoxins in barley, sorghum, teff (Eragrostis tef) and wheat from Ethiopia has been studied. Samples were analyzed for aflatoxin B1 (AFB1), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) using high performance liquid chromatography
(HPLC) and for fumonisins (FUM) using enzyme linked immunosorbent assay (ELISA). AFB1 and OTA were detected in samples of
all the four crops. AFB1 was detected in 8.8% of the 352 samples analyzed at concentrations ranging from trace to 26 μg kg−1. OTA occurred in 24.3% of 321 samples at a mean concentration of 54.1 μg kg−1 and a maximum of 2106 μg kg−1. DON occurred in barley, sorghum and wheat at 40–2340 μg kg−1 with an overall incidence of 48.8% among the 84 mainly ‘suspect’ samples analyzed; NIV was co-analyzed with DON and was detected
at 40 μg kg−1 in a wheat sample and at 50, 380, and 490 μg kg−1 in three sorghum samples. FUM and ZEN occurred only in sorghum samples with low frequencies at concentrations reaching 2117
and 32 μg kg−1, respectively. The analytical results indicate higher mycotoxin contamination in sorghum, which could be related to the widespread
storage of sorghum grain in underground pits leading to elevated seed moisture contents. This is the first report on the occurrence
of OTA in teff. 相似文献
15.
Fusarium toxins are secondary metabolites produced byfungi of these genera in many commodities under certain conditions. A study was carried out to investigate the co-occurrence of
zearalenone (ZEN), deoxynivalenol (DON) and fumonisins (FB1 and FB2) in 52 samples of mixed-feed for poultry contaminated withFusarium verticillioides. The zearalenone and deoxynivalenol were checked using immunoaffinity column and the extraction of fumonisin was performed
by strong anion exchange (SAX) solid phase column. Detection and quantification were determined by high performance liquid
chromatography (HPLC). The limit of detection was 5 μg/kg for ZEN, 100 μg/kg for DON and 50 and 100 μg/kg for FB1 and FB2 respectively.Fusarium toxins were detected in 20 samples. Sixteen samples were positive for ZEN (30.7%) presenting levels that ranged from 7.4
μg/kg to 61.4 μg/kg (mean=27.0 μg/kg). 13.5% of the samples presented contaminations of DON, with levels ranging from 100.0
μg/kg to 253 μg/kg (mean=l18.07 μg/kg). FB1 was detected in 19.2% of samples, with levels ranging from 50.0 μg/kg to 110.0 μg/kg (mean=73.6 μg/kg). FB2 was not detected
in any sample. In positive samples simultaneously contamination with two or three mycotoxins were detected in 9 of them (17.3%). 相似文献
16.
A sensitive and reliable method is described for the determination of ochratoxin A (OTA) in maize. An extraction and clean-up procedure was used, with chloroform-phosphoric acid as the extractant, and liquid-liquid partition and anion-exchange chromatography (SAX columns) for the clean-up. Quantification of toxin is achieved by high performance liquid chromatography (HPLC). Recoveries were between 81-94 % at 3-90 ng/g levels. The detection limit was 0.02 ng. 相似文献
17.
The Alternaria mycotoxin tenuazonic acid (TA) was quantified in fruit juices (n = 50), cereals (n = 12) and spices (n = 38) using a recently developed stable isotope dilution assay (SIDA). [13 C6,15 N]-TA was used as the internal standard. Method validation revealed low limits of detection (LODs) of 0.15 μg/kg (fruit juices),
1.0 μg/kg (cereals) and 17 μg/kg (spices). The respective limits of quantitation were about three times higher. Recovery was
about 100% for all matrices. The precision (relative standard deviation of replicate analyses of naturally contaminated samples)
was 4.2% (grape juice; 1.7 μg/kg), 3.5% (whole wheat flour; 36 μg/kg) and 0.9% (curry powder; 215 μg/kg). The median content
of TA in the analyzed samples was 1.8 μg/kg (fruit juices), 16 μg/kg (cereals) and 500 μg/kg (spices). Positive samples amounted
to 86% (fruit juices), 92% (cereals) and 87% (spices). 相似文献
18.
A total of 120 different samples belonging to 24 kinds of spices collected from different places atAssiut Governorate (Egypt) were examined for the natural occurrence of mycotoxins. TLC analysis of spice extracts revealed the presence of aflatoxins
(8–35 μg/kg) in 16 samples of anise, black pepper, caraway, black cumin, fennel, peppermint, coriander and marjoram, sterigmatocystin
(10–23 μg/kg) in ten samples of red pepper, caraway, cumin and marjoram and citrinin (8–12 ⧎g/kg) in two samples of black
cumin, while ochratoxin A and zearalenone could not be detected. 相似文献
19.
Farm workers are often exposed to high concentrations of airborne organic dust and fungal conidia, especially when working
with plant materials. The purpose of this investigation was to study the possibility of exposure to the mycotoxin ochratoxin
A (OTA) through inhalation of organic dust and conidia. Dust and aerosol samples were collected from three local cowsheds.
Aerosol samples for determination of total conidia and dust concentrations were collected by stationary sampling on polycarbonate
filters. Total dust was analysed by gravimetry, and conidia were counted using scanning electron microscopy. A method was
developed for extraction and determination of OTA in small samples of settled dust. OTA was extracted with a mixture of methanol,
chloroform, HCI, and water, purified on immunoaffinity column, and analysed by ion-pair HPLC with fluorescence detection.
Recovery of OTA from spiked dust samples (0.9–1.0 μg/kg) was 74% (quantitation limit 0.150 μg/kg). OTA was found in 6 out
of 14 settled dust samples (0.2–70 μg/kg). The total concentration of airborne conidia ranged from < 1.1 × 104 to 3.9 × 155 per m3, and the airborne dust concentration ranged from 0.08 to 0.21 mg/m3. Conidia collected from cultures of Penicillium verrucosum and Aspergillus ochraceus contained 0.4–0.7 and 0.02–0.06 pg OTA per conidium, respectively. Testing of conidial extracts from these fungi in a Bacillus subtilis bioassay indicated the presence of toxic compounds in addition to OTA. The results show that airborne dust and fungal conidia
can be sources of OTA. Peak exposures to airborne OTA may be significant, e.g., in agricultural environments.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
20.
A simple method for the rapid analysis of pristane has been designed using a heptane extract of the aqueous sample followed
by separation and detection by gas chromatography. Ascites fluid lots from three monoclonal antibodies (MAbs) and their purified
preparations were analysed using the procedure. The highest detected level of pristane was 600 μg/mL in a single lot of ascites
fluid with other values less than 140 μg/ml. For the purified samples, no pristane was detected down to the demonstrated limit
of 4 μg/mg of MAb. 相似文献