Influence of temperature and pH on the degradation of deoxynivalenol (DON) in aqueous medium: comparative cytotoxicity of DON and degraded product

Deoxynivalenol (DON), a toxic fungal metabolite, is stable under different processing conditions; however, its stability in aqueous medium at different temperatures and low pH (1–2) (present in the gastrointestinal tract) has not been investigated. In the present study, DON standard was used to study the influence of temperature and pH on DON stability in aqueous medium, the characterisation of the degraded product, and the comparative toxicity profile of the degraded and the parent compound. The results suggest that standard DON was unstable at 125–250°C showing 16–100% degradation whereas DON at pH 1–3 had 30–66% degradation, with a concomitant increase in the formation of a degraded product. Further ESI-MS characterisation of the dominant precursor ion of the HPLC eluate of the DON-degraded product was found to be m/z 279, resembling the known metabolite DOM-1. The degraded product of DON was reconfirmed as DOM-1 by comparison with standard DOM-1 and both gave a similar λ_max at 208 nm. Comparative studies of both standard DOM-1 and the degraded product of DON showed no cytotoxicity up to 6400 ng ml^–1 while significant cytotoxicity was observed for DON (400 ng ml^–1). The results suggest that a highly acidic environment (pH 1–2) could be responsible for the de-epoxydation of DON leading to the formation of DOM-1.     

Determination of 2,6-diisopropylnaphthalene (DIPN) and n-dibutylphthalate (DBP) in food and paper packaging materials from US marketplaces

A gas chromatography-ion-trap tandem mass spectrometry procedure was developed for the determination of 2,6-diisopropylnaphthalene (DIPN) and n-dibutylphthalate (DBP) in domestic and imported paper packages and food sold in US marketplaces. The procedure involved ultrasonic extraction with dichloromethane, followed by analysis with the gas chromatography-ion-trap tandem mass spectrometry. Calibration curves for DIPN and DBP were achieved with concentrations ranging from 0.01 to 10 µg ml^?1 and the corresponding r ² values were 0.9976 and 0.9956, respectively. In most of the fortified samples the recoveries were higher than 80% with a relative standard deviation (RSD) <10%. Using this procedure, it was found that less than 20% of the tested domestic packages and more than 60% of the tested imported food packages contained both DIPN and DBP. The concentrations of DIPN and DBP ranged from 0.09 to 20 mg kg^?1 and 0.14 to 55 mg kg^?1, respectively, with most of the DINP and DBP levels lower than 20 mg kg^?1. DIPN was not detected (<0.01 mg kg^?1) in 41 food samples and DBP was only detected in two domestic and four imported food samples with concentrations ranging from <0.01 to 0.81 mg kg^?1.     

Determination of aflatoxin M1 in milk by triple quadrupole liquid chromatography-tandem mass spectrometry

A sensitive and reliable method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with an electrospray-positive ionization method was developed for the determination of aflatoxin M₁ in milk. This method includes simple extraction of the sample with acetonitrile by ultrasonic, separation on an MGIII-C₁₈ column using 0.01% formic acid buffer/acetonitrile (60 : 40, v/v) as mobile phase, and MS/MS detection using multiple reaction-monitoring mode. Average recoveries of aflatoxin M₁ from spiked samples at concentrations of 0.02 and 1 ng ml^?1 ranged from 77% to 94%, with a 6% relative standard deviation. The limit of detection and limit of quantification were 0.006 and 0.02 ng ml^?1, respectively. The standard curve was linear between 0.02 and 20.0 ng ml^?1. The recommended method is simple, rapid, specific and reliable for the routine monitoring of aflatoxin M₁ in milk.     

Occurrence of deoxynivalenol and its 3-β-D-glucoside in wheat and maize

Deoxynivalenol-3-β-D-glucoside (D3G), a phase II plant metabolite of the mycotoxin deoxynivalenol (DON), occurs in naturally Fusarium-contaminated cereals. In order to investigate the frequency of occurrence as well as the relative and absolute concentrations of D3G in naturally infected cereals, 23 wheat samples originating from fields in Austria, Germany and Slovakia as well as 54 maize samples from Austrian fields were analysed for DON and D3G by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Both analytes were detected in all the 77 field samples. DON was found at levels from 42 to 4130 ng g^?1 (977 ± 1000 ng g^?1 on average). The D3G concentrations in all cereal samples were in the range 10–1070 ng g^?1 (216 ± 253 ng g^?1 on average), corresponding to about 5–46 mol% of their DON concentrations (15 ± 8 mol% on average).     

Multitoxin extraction and detection of trichothecenes in cereals: an improved LC‐MS/MS approach

BACKGROUND: Many multiresidual methods to evaluate natural occurrence of Fusarium toxins are already reported in the scientific literature but a new rapid, reliable, cost‐efficient and high‐sensitivity method for the simultaneous determination of several fusariotoxins is always welcome. Nivalenol (NIV), deoxynivalenol, fusarenon‐X (FUS‐X), 3‐acetyldeoxynivalenol, diacetoxyscirpenol (DAS), HT‐2 toxin, T‐2 toxin, neosolaniol (NEO), zearalanone and zearalenone (ZON) belong to the most common mycotoxins in food matrix grains, e.g., wheat and maize. The proposed method is a multitoxin analytical method that combines high‐performance liquid chromatography (HPLC), atmospheric pressure chemical ionization (APCI), triple‐quadrupole tandem mass spectrometry (LC‐MS/MS) under the selected reaction monitoring (SRM) mode, and it is focused on the optimization of the sample preparation without the need for any cleanup. RESULTS: Three different methods for sample preparation and for the simultaneous extractions of the above‐mentioned fusariotoxins were tested: two of these were followed by a different cleanup step for comparison, while the extraction method proposed in this work, which uses an 84% (v/v) acetonitrile aqueous solution, sample homogenization and subsequent filtration, was validated without any further cleanup step. CONCLUSION: Calibration curves for all analytes are linear, except DAS, HT‐2 and ZON, over the working range of 10–1000 µg kg^?1. The calibration curve of DAS was linear between 10 and 500 µg kg^?1, although the curves of HT‐2 and ZON were linear in the range 10–250 µg kg^?1. Squared correlation coefficients (R²) were in the range 0.995–0.998 for the all point calibration curves. The lowest limits of detection (LOD) were found for DON and ZAN with 0.5 and 0.2 µg kg^?1, respectively, while the highest LODs were obtained for NIV, FUS‐X and NEO, with 3.3 µg kg^?1 for each toxin. Copyright © 2009 Society of Chemical Industry     

Occurrence of Fusarium mycotoxins in maize imported into the UK, 2004–2007

This study examined a total of 82 consignments of French and Argentinean raw maize as received at maize mills in the UK between 2004 and 2007. Samples were analysed for deoxynivalenol (DON), nivalenol (NIV), other trichothecenes, zearalenone (ZON), and fumonisins B₁, B₂, and B₃ (FB₁, FB₂, and FB₃) using fully validated analytical methods with limits of quantification of 10 µg kg^?1 for DON, NIV, and each fumonisin mycotoxin and 3 µg kg^?1 for ZON. All samples except two containing fumonisins met the European Commission statutory maximum permissible levels for DON, ZON, and FB₁ + FB₂ as operating in 2007. The maximum concentrations found for DON, NIV, ZON, and FB₁ + FB₂ were 444, 496, 165 and 5002 µg kg^?1, respectively. Fumonisins were detected in almost every sample with 65% of Argentinean maize containing more than 1000 µg kg^?1 of FB₁ + FB₂. In contrast, ZON was not detectable in almost 50% of consignments. During this period there was a distinct difference in mycotoxin concentrations between harvests and geographic origin. Flint maize from Argentina usually contained lower concentrations of DON and related trichothecenes and higher levels of fumonisins than maize from France, although concentrations of fumonisins up to 2000 µg kg^?1 or greater occurred in samples from both regions. The incidence and concentrations of fumonisins were similar to those in a similar previous survey, while zearalenone concentrations were lower. The distribution of mycotoxins in multi-hold ships was also investigated showing that fumonisins were much more evenly distributed than DON, thus indicating their general level in the ship as a whole. The effect of cleaning regimes was found to be very variable, especially for DON, ranging from no removal of mycotoxins to greater than 50% in some instances, but was not related to concentration. Evidence here suggests that while cleaning is essential for removing foreign bodies before milling, it cannot be used as a reliable tool for reducing mycotoxins.     

Occurrence and intake of deoxynivalenol in cereal-based products marketed in Korea during 2007–2008

The occurrence of deoxynivalenol (DON) was investigated in 514 cereal-based products (corn-based, n = 125; barley-based, n = 96; wheat-based, n = 94; rice-based, n = 199) marketed in Korea during 2007?2008, and estimates of DON intake were determined. Samples were analysed by high-performance liquid chromatography (HPLC) with ultraviolet light (UV) detection after immunoaffinity clean-up. The limits of detection (LOD) and limits of quantification (LOQ) were 2.2 and 5.6 µg kg^–1, respectively. Recoveries and repeatability expressed as coefficients of variation (CV) were 82.3–100% and 2.4–15.3% in beer, bread and dried corn. The incidences and mean levels of DON were 56% and 68.9 µg kg^?1 for corn-based products, 49% and 24.1 µg kg^?1 for wheat-based products, 43% and 7.5 µg kg^?1 for barley-based products, and 16% and 3.4 µg kg^?1 for rice-based products, respectively. The estimated daily intake of DON from the consumption of rice-based, wheat-based, barley-based and corn-based products were 0.0038 µg kg^?1 bw day^?1, 0.0032 µg kg^?1 bw day^?1, 0.0015 µg kg^?1 bw day^?1 and 0.0002 µg kg^?1 bw day^?1, respectively. These values represent 0.38%, 0.32%, 0.25% and 0.01% of the provisional maximum tolerable daily intake (PMTDI) of 1 µg kg^?1 bw day^?1. These results indicate that rice-based products are major contributors to DON exposure in Korea, even though the current exposure level is unlikely to cause adverse health effects.     

Deposition and depletion of maduramicin residues in eggs after oral administration to laying hens determined by LC-MS

The coccidiostat maduramicin has been approved as a feed additive for chickens and turkeys, although it is prohibited for use in laying hens. In the present study, laying hens were divided into three groups and fed for 14 days with medicated feed containing maduramicin, at three different concentrations: 50, 100 and 500 µg kg^?1. Eggs were collected during treatment and for 26 days after the end of feeding with medicated feed. Maduramicin residues were found exclusively in egg yolk, with the highest concentration in egg yolk of 459 µg kg^?1 for the highest dose. The maximum concentration of maduramicin in whole egg was 16.6 µg kg^?1 for the group receiving feed containing the maximum permitted level of maduramicin in feed (50 µg kg^?1). The half-life of elimination of maduramicin, calculated for post-treatment days 1–10, was 6.5 days. Twelve days after drug administration, the concentration of the maduramicin in egg yolk for Group 3 (fed with 500 µg kg^?1 maduramicin) still exceeded 20 µg kg^?1, while the concentrations for Groups 1 and 2 were 1.2 and 2.7 µg kg^?1, respectively.     

Quantitative determination of mycotoxins in urine by LC-MS/MS

Naturally occurring mycotoxins are responsible for a wide array of adverse health effects. The measurement of urinary mycotoxin levels is a useful means of assessing an individual's exposure, but the development of sensitive and accurate analytical methods for detecting mycotoxins and their metabolites in urine samples is challenging. Urinary mycotoxins are present in low pg ml^–1 concentrations, and the chromatographic identification of their metabolites can be obscured by other endogenous metabolites. We developed an analytical method focused on the selection of two appropriate multiple-reaction monitoring transition for unambiguous identification and quantification of carcinogenic aflatoxin M₁ (AFM₁), ochratoxin A (OTA) and fumonisin B₁, B₂ (FB₁, FB₂) in urine samples from a small volunteer group in a pilot study. AFM₁, OTA, FB₁ and FB₂ were concentrated selectively, interfering substances were removed using an immunoaffinity column (IAC), and mycotoxins were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in combination with a stable-isotope standard-dilution assay (SIDA). The method was sensitive enough to measure mycotoxins and their metabolites at pg ml^–1 levels in urine. The combination of LC-MS/MS and SIDA was critical to distinguishing pseudo-OTα interference from genuine OTα. Twelve urine samples contained OTA ranging from 0.013 to 0.093 ng ml^?1 (mean = 0.031 ng ml^?1). AFM₁ were detected in one sample at a 0.002 ng ml^?1 level, while FB₁ and FB₂ were undetectable in all 12 samples. None of the samples in this pilot study contained a detectable level of OTα, despite the presence of OTA, and this may suggest the need for further epidemiological investigation of OTA exposure in the Korean population.     

Determination of phthalates in raw bovine milk by gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS) and dietary intakes

Low levels of phthalates, including di(2-ethylhexyl) phthalate (DEHP), in raw bovine milk were determined using gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS). A fast and convenient process of sample treatment combined with TOF-MS analysis (medium resolution >5000), yielded good recoveries (85–125%) and low limits of detection (<0.002 mg kg^?1). The most commonly used phthalate, DEHP, was found in 15 out of 30 samples monitored in this study. DEHP concentrations in raw milk ranged from not detected to 0.154 mg kg^?1, and the mean concentration was 0.057 mg kg^?1. The dietary intake of DEHP was about 0.004 mg kg^?1 body weight day^?1 if a child (24 months, 13 kg body weight) drinks 1 L day^?1 of milk that contains the mean concentration of DEHP found in raw milk. The estimated dietary intake corresponded to 8% of the European Union tolerable daily intake (TDI) of 0.05 mg kg^?1 body weight day^?1. Dimethyl phthalate (DMP) and di-n-butyl phthalate (DBP) were found from two and 20 samples, respectively, at low levels. Diethyl phthalate (DEP), butylbenzyl phthalate (BBP), and di-n-octyl phthalate (DnOP) were not found in any of the samples.     

Deoxynivalenol suppresses circulating and splenic leukocyte subpopulations in BALB/c mice: dose response,time course and sex differences

It was hypothesized that suppression of peripheral blood leukocyte subsets were markers of exposure to dietary deoxynivalenol (DON), a Fusarium graminearum mycotoxin in grain, at 1.0 mg kg^?1 but not at lesser doses in BALB/c mice. Groups of 10 female and 10 male BALB/c mice were fed 0, 0.25, 0.5, 1.0, and 2.0 mg kg^?1 DON for 14 and 28 days. Using flow cytometry with staining for leukocyte surface markers, the percentage of CD19⁺ leukocytes (B cells) in peripheral blood was decreased in both sexes of BALB/c mice after 14 days of exposure to 1.0 or 2.0 mg kg^?1 DON, whereas exposure to DON over 28 days did not inhibit B cells compared to the control diet. The percentage of mononuclear cells in peripheral blood was decreased in female BALB/c mice fed 1 and 2 mg kg^?1 DON after 14 days compared with control diet. The percentage of CD11b⁺ leukocytes (monocytes) in peripheral blood and total CD11b⁺ splenic leukocytes were decreased only in female mice fed 1.0 and 2.0 mg kg^?1 DON after 28 days compared with control diet, which shows the greater sensitivity to DON in females compared to males. It was concluded that BALB/c mice adapted to DON exposure because peripheral blood cellular effects of DON at 14 days disappeared by 28 days with the exception of monocyte changes in females. This suggests that female sex hormones potentiate one potential marker of DON immunotoxicity in BALB/c mice.     

Rapid multi-class multi-residue method for the confirmation of chloramphenicol and eleven nitroimidazoles in milk and honey by liquid chromatography-tandem mass spectrometry (LC-MS)

A confirmatory method was developed to allow for the analysis of eleven nitroimidazoles and also chloramphenicol in milk and honey samples. These compounds are classified as A6 compounds in Annex IV of Council Regulation 2377/90 (European Commission 1990) and therefore prohibited for use in animal husbandry. Milk samples were extracted by acetonitrile with the addition of NaCl; honey samples were first dissolved in water before a similar extraction. Honey extracts underwent a hexane wash to remove impurities. Both milk and honey extracts were evaporated to dryness and reconstituted in initial mobile phase. These were then injected onto a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system and analysed in less than 9 min. The MS/MS was operated in multiple reaction monitoring (MRM) mode with positive and negative electrospray ionization. The method was validated in accordance with Commission Decision 2002/657/EC and is capable of analysing metronidazole, dimetridazole, ronidazole, ipronidazole and there hydroxy metabolites hydroxymetronidazole, 2-hydroxymethyl-1-methyl-5-nitroimidazole, and hydroxyipronidazole. The method can also analyse for carnidazole, ornidazole, ternidazole, tinidazole, and chloramphenicol. A recommended level of 3 µg l^?1/µg kg^?1 for methods for metronidazole, dimetridazole, and ronidazole has been recommended by the Community Reference Laboratory (CRL) responsible for this substance group, and this method can easily detect all nitroimidazoles at this level. A minimum required performance level of 0.3 µg l^?1/µg kg^?1 is in place for chloramphenicol which the method can also easily detect. For nitroimidazoles, the decision limits (CCα) and detection capabilities (CCβ) ranged from 0.41 to 1.55 µg l^?1 and from 0.70 to 2.64 µg l^?1, respectively, in milk; and from 0.38 to 1.16 µg kg^?1 and from 0.66 to 1.98 µg kg^?1, respectively, in honey. For chloramphenicol, the values are 0.07 and 0.11 µg l^?1 in milk and 0.08 and 0.13 µg kg^?1 in honey. Validation criteria of accuracy, precision, repeatability, and reproducibility along with measurement uncertainty were calculated for all analytes in both matrices.     

Evaluation of fumonisin biomarkers in a cross-sectional study with two high-risk populations in China

Levels of serum and urinary sphinganine (Sa) and sphingosine (So), the Sa/So ratio, and urinary-free fumonisin B₁ (FB₁) were determined in a cross-sectional study consisting of 43 adults in Huaian and 34 adults in Fusui, China. Home-produced corn had 100% contamination with FB₁. There were 93.0% (40/43) of Huaian subjects and 52.9% (18/34) of Fusui subjects with daily FB₁ intakes greater than 2 µg kg^?1 body weight, which showed a significant difference (p < 0.01). Levels of sphinganine and sphingosine and the Sa/So ratio were not correlated with levels of dietary exposure. The median level of the serum Sa/So ratio in Huaian subjects (0.41, range = 0.14–0.85) was significantly lower than that in Fusui subjects (0.78, range = 0.57–1.08) (p < 0.01). The median level of the urinary Sa/So ratio was also significantly lower in Huaian subjects (0.31, range = 0.08–1.33) than in Fusui subjects (0.57, range = 0.03–2.52) (p < 0.01). Urinary-free FB₁ was detected in 83.7% (36/43) of Huaian samples and in 82.4% (28/34) of Fusui urine samples (p > 0.05). However, the median level of urinary-free FB₁ in Huaian subjects, 3.91 (range = 0.06–253.61) ng mg^?1 creatinine, was significantly higher than 0.39 (range = 0.01–3.72) ng mg^?1 creatinine found in Fusui subjects (p < 0.01). These results suggest that urinary-free FB₁ may be a potential biomarker for human fumonisin exposure, while further validation is needed in human epidemiological and intervention studies.     

Assessment of the dietary habits and polycyclic aromatic hydrocarbon exposure in primary school children

Thirty Italian children, 7–9 year aged, living in Naples were investigated on their dietary habits and on polycyclic aromatic hydrocarbon (PAH) exposure by a food diary-questionnaire and one week duplicate diet sample analyses. Daily total food consumption mean value was 632 ± 215 g day^?1, median value 613 g day^?1. The daily energy intake and the diet composition meanly agreed with the official guidelines for the Italian children. Sixteen PAHs were simultaneously detected and, according to the European Food Safety Authority (EFSA) approach, benzo[a]pyrene; benzo[a]pyrene + chrysene (PAH2); PAH2 + benz[a]anthracene + benzo[b]fluoranthene (PAH4); PAH4 + benzo[k]fluoranthene + benzo[ghi]perylene + dibenz[a, h]anthracene + indeno[1,2,3-cd]pyrene (PAH8) were considered in evaluating the children's dietary exposure to PAHs. The benzo[a]pyrene (BaP) median concentrations in foods varied from 0.06 to 0.33 µg kg^?1. Only three samples of cooked foods (one fish and two meat samples) exceeded legal limits fixed by the European Union for BaP. Daily median intakes of benzo[a]pyrene, PAH2, PAH4, and PAH8 were 153; 318; 990; 1776 ng day^?1; their median exposure values were 5; 10; 28; 54 ng kg^?1 bw day^?1. The Margins of Exposure (MOEs) in median consumers agreed with the EFSA safety values except for PAH8.     

Transfer of aflatoxin B1 and fumonisin B1 from naturally contaminated raw materials to beer during an industrial brewing process

The aim of this research was to determine the fate of aflatoxins (AFs) and fumonisins (FBs) naturally occurring in raw materials (maize grit and malted barley) during four industrial brewing processes. The aflatoxin B₁ (AFB₁) level in raw materials varied from 0.31 to 14.85 µg kg^?1, while the fumonisin B₁ (FB₁) level (only in maize grit) varied from 1146 to 3194 µg kg^?1. The concentration in finished beer ranged from 0.0015 to 0.022 µg l^?1 for AFB₁ and from 37 to 89 µg l^?1 for FB₁; the other aflatoxins and fumonisin B₂ were not found in beer samples. The average percentage of toxins recovered in finished beer, referring to the amounts contained in raw materials, were 1.5% ± 0.8% for AFB₁ and 50.7% ± 4.7% for FB₁. These results were mainly due to the different solubility of the two mycotoxins during the mashing process. If raw materials comply with the limits fixed by European Commission Regulations, the contribution of a moderate daily consumption of beer to AFB₁ and FB₁ intake does not contribute significantly to the exposure of the consumer.     

Lipophilic toxin profiles detected in farmed and benthic mussels populations from the most relevant production zones in Southern Chile

Lipophilic toxins associated with diarrhoeic toxins were found in Mytilus chilensis (Blue mussels) and Aulacomya ater (Ribbed mussels). These shellfish samples were collected from Chiloe Island, Southern Chile. The samples were tested by liquid chromatography–tandem mass spectrometry (LC-MS/MS). After the analysis, four toxins were found: DTX-1, DTX-3, YTX and PTX. All toxins were identified by comparing their HPLC retention times with those of analytical standards and confirmed by LC-MS/MS. Dinophysistoxin-1 (DTX-1) and dinophysistoxin-3 (DTX-3) toxins were the major components within the mussel extracts. Nevertheless, the percentages of these toxins differed depending on the area they were collected from and/or the sampling date. The levels detected in Butacheuques Island for okadaic acid (OA) was 267?±?3.5?µg OA?eq?kg^?1 (p?<?0.05) and for DTX-3 was 183.4?±?7.5?µg?kg^?1 in ribbed mussels. Pectenotoxin (PTX) and yessotoxin (YTX) were the toxins detected in minor proportions in the toxic profile of the bivalves. The maximum concentration of YTX detected in ribbed mussels was 85.2?±?2.8?µg?kg^?1 in Mechuque Island, whereas the PTX-2 level in ribbed mussels was 82.0?±?2.4?µg?kg^?1 in Cailin Island. Analogues of YTX and PTX-2 were not detected in any of the analysed mussels, which did not support the supposed presence of isomers of toxins as a result of the enzymatic metabolism of bivalves. This study found evidence proving co-occurrence of lipophilic toxins – like PTX and YTX – with diarrhoeic toxin in samples collected in Southern Chile, which is, to date, the more complex mix of lipophilic toxins ever found in mussels samples from Southern Chile.     

Optimisation of the determination of deoxynivalenol in wheat flour by HPLC and a comparison of four clean-up procedures

The determination of deoxynivalenol (DON) in wheat flour by liquid chromatography with photodiode array (PDA) detection was optimised. Response surface methodology (RSM) was used to determine the optimum chromatographic conditions for the determination of DON. The influence of three variables, acetonitrile (ACN) volume in mobile phase (9.5–24.5, v/v), flow rate (0.5–1.5 ml min^?1) and wavelength (215–221 nm) on DON peak area was evaluated. The best separation was achieved using a symmetry column (150 × 3.9 mm; particle size 5 µm) by isocratic elution (1.0 ml min^?1) and a mobile phase consisting of ACN/water in the ratio 17 : 83 (v/v). UV detection was performed at 218 nm. Linear calibration curves were constructed in the concentration range 1–1000 ng ml^?1. The detection limit measured as the signal-to-noise ratio (3 : 1) was 0.03 ng ml^?1. RSM results showed that the experimental data could be adequately fitted to a second-order polynomial model with multiple regression coefficients (R ²) of 0.968. The efficiency of four clean-up procedures for wheat flour extract was compared. Recovery of DON using a Mycosep #225 column was highest with a value of 99%, while that of Mycosep #227 was 65%. In contrast, DON recovery using immunoaffinity columns (IAC) and an Oasis® HLB column was only 53 and 42%, respectively. The trueness of the method using the Mycosep #225 column was established with a certified reference material CRM 379. The result obtained from three replicates was 0.66 ± 0.04 µg g^?1 and the certified value was 0.67 µg g^?1.     

Mycotoxins in fuel ethanol co‐products derived from maize: a mass balance for deoxynivalenol

BACKGROUND: Three matrices—corn (maize) meal, distiller's dried grains with solubles (DDGS) and condensed distiller's solubles (CDS)—were sampled in sequence from a continuous dry‐milling process plant for the determination of mass balance of deoxynivalenol (DON). Four commercially available enzyme‐linked immunosorbent assay (ELISA) kits were evaluated for their ability to measure the presence of DON. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) was used as standard method to detect DON and other Fusarium toxins. RESULTS: The concentrations of DON in DDGS and especially CDS were overestimated or underestimated by ELISA. However, for both matrices, all ELISA methods were not significantly different in their mean results from the LC/MS/MS standard, although the variability in results was much higher. DON concentrations in the CDS and the final DDGS co‐product were significantly higher (P ≤ 0.01) than in the starting material (corn grain). Toxin concentration increased by a factor of 3 on a dry weight basis in DDGS compared with the starting corn and by a factor of 4 in CDS. Mean concentration of DON in CDS was four times higher (7.11 mg kg^?1) than in corn grains (1.80 mg kg^?1) and 1.4 times higher than in DDGS (5.24 mg kg^?1). Mass balance calculations showed that CDS was the main source of contamination of DON, comprising ca 70% of the toxin found in the final product (DDGS). Most DON (87%) was accounted for by this analysis. CONCLUSION: Concentrations in the grain corn entering ethanol plants should be close to the dietary values recommended for swine in Canada and the USA for DON (1 mg kg^?1). Small amounts of acetyldeoxynivalenol and DON glucoside were also found in the three matrices along with a small amount of zearalenone. Unlike the situation for DON, the DON glucoside was not concentrated into DDGS and CDS, indicating that it was hydrolysed during the fermentation process. Copyright © 2009 Society of Chemical Industry     

Development of an analytical method and survey of foods for furan, 2-methylfuran and 3-methylfuran with estimated exposure

Furan has been found to form in foods during thermal processing. These findings, a classification of furan as a possibly carcinogenic to humans, and a limited amount of data on the concentration of furan in products on the Canadian market prompted the authors to conduct a survey of canned and jarred food products. Methyl analogues of furan, 2-methylfuran and 3-methylfuran, were analysed concurrently with furan via a newly developed isotope dilution method, as these analogues were detected in foods in the authors’ earlier work and are likely to undergo a similar metabolic fate as furan itself. The paper reports data on 176 samples, including 17 samples of baby food. The vast majority of samples were packaged in cans or jars. Furan was detected above 1 ng g^?1 in all non-baby food samples with a median of 28 ng g^?1 and concentrations ranging from 1.1 to 1230 ng g^?1. Also, 96% of these samples were found to contain 2-methylfuran above 1 ng g^?1 with a median of 12.8 ng g^?1 and a maximum concentration of 152 ng g^?1, while 81% of samples were found to contain 3-methylfuran above 1 ng g^?1 with a median of 6 ng g^?1 and a maximum concentration of 151 ng g^?1. Similarly, furan was detected above 1 ng g^?1 in all baby food samples with a median of 66.2 ng g^?1 and concentrations ranging from 8.5 to 331 ng g^?1. Also, 100% of these samples were found to contain 2-methylfuran above 1 ng g^?1 with a median of 8.7 ng g^?1 and a maximum concentration of 50.2 ng g^?1, while 65% of samples were found to contain 3-methylfuran above 1 ng g^?1 with a median of 1.6 ng g^?1 and a maximum concentration of 22.9 ng g^?1. Additionally, three coffee samples were analysed ‘as is’, without brewing, and were found to have high levels of furans, especially 2-methylfuran, at a maximum of 8680 ng g^?1. Using this data set, dietary exposures to furan and total furans were calculated. Average furan and total furan intakes by adults (≥20 years) were estimated at approximately 0.37 and 0.71 µg kg^?1 of body weight day^?1 respectively.