高效液相色谱-串联质谱法测定杂粮豆类中11种真菌毒素

利用高效液相色谱-串联质谱建立杂粮豆类中11种真菌毒素（包括黄曲霉毒素B1、B2、G1、G2、赭曲霉毒素A、T-2毒素、脱氧雪腐镰刀菌烯醇、伏马毒素B1、B2和B3、玉米赤霉烯酮）同时检测的方法。实验对提取溶剂、提取时间和净化方式等进行优化,建立双体系联合提取方法,首先采用甲醇-水（70∶30,V/V）体系提取,再以乙腈-水（84∶16,V/V）体系二次提取,提取时间3 min,在此基础上采用C18吸附剂进行净化处理。结果表明,11种毒素的线性范围良好,相关系数大于0.999,添加回收率为70.0%～108%,相对标准偏差为1.3%～8.6%。所建方法简单、快速、灵敏度高、重复性好,可满足杂粮豆类中11 种真菌毒素的同时检测需要。     

Toxicity profile of commercially produced indigenous banana beer

Mycotoxins, together with endotoxins, represent important classes of naturally occurring contaminants in food products, posing significant health risks to consumers. The aim of this study is to investigate the occurrence of both Fusarium mycotoxins and endotoxins in commercially produced traditional banana beer. Two brands of commercially produced traditional banana beer were collected from a local retail market in Kigali, Rwanda. Beer samples were analysed for the presence of deoxynivalenol (DON), fumonisin B(1) and zearalenone (ZEA), using an enzyme-linked immuno-sorbent assay (ELISA) method. The quantification of bacterial endotoxin using Limulus amoeboecyte lysate (LAL) assay was also conducted. The contamination levels were 20 and 6.7?μg?kg(-1) for DON; 34 and 31.3?μg?kg(-1) for FB(1); 0.66 and 2.2?μg?kg(-1) for ZEA in brands A and B of the beers, respectively. Results indicate that the levels of Fusarium toxins and bacterial endotoxin reported in this study did not pose adverse human health effects as a result of drinking/consuming banana beer. However, exposure to low/sub-threshold doses or non-toxic levels of endotoxins magnifies the toxic effect of xenobiotic agents (e.g. fungal toxins) on liver and other target organs. Considering Fusarium toxins and/or endotoxin contamination levels in other agricultural commodities intended for human consumption, health risks might be high and the condition is aggravated when beer is contaminated by mixtures of the mycotoxins, as indicated in this study.     

Determination of Furfural in Beer by High‐Performance Liquid Chromatography with Solid‐Phase Extraction

Furfural is a sensitive indicator of beer staling. A new solid‐phase extraction (SPE) column PEP‐SPE (Polar‐Enhanced Polymer, 500 mg/6 mL) was used to develop a method for extraction of furfural from beer. The PEP‐SPE column retains furfural with higher selectivity than the commonly used C₁₈‐SPE column. Satisfactory precisions were obtained with %RSD (n = 6) less than 2.2% for peak areas. Recovery rates were in the range of 99.7–100.1% due to the simple treatment and good resolution. The detection limit was 5 μg/L. Furfural concentration ranged from 10 to 32 μg/L in twelve fresh beer samples. A noticeable increase in furfural content was found after beer samples were kept at 35°C for seven days. The calculated correlation coefficient between taste panel scores for beer freshness and the furfural content of aged beer samples was ?0.65, which showed a good inverse correlation between freshness marks and furfural content.     

Co-occurrence of aflatoxin B1, fumonisin B1, ochratoxin A and zearalenone in cereals and peanuts from C?te d'Ivoire.

This survey examined 30 samples of rice (n = 10), maize (n = 10) and peanuts (n = 10) from C?te d'Ivoire for aflatoxin B1, fumonisin B1 and zearalenone using immunoassays, and ochratoxin A using a validated HPLC method with fluorescence detection. In C?te d'Ivoire, as in other countries, several mycotoxins are present in the same commodities. These mycotoxins are from different structural families: aflatoxin B1, fumonisin B1, zearalenone and ochratoxin A, normally produced by fungal species from Aspergillus, Penicillium and Fusarium genera. Some samples contained four mycotoxins (86%). Four peanuts samples did not show ochratoxin A (14%), whereas they contained aflatoxin B1 concentrations above the EU regulatory limits. Concentrations of ochratoxin A, zearalenone and fumonisin B1 were low and may not cause problems per se; however, fears remain that the tolerable daily intake may be exceeded due to eating habits and synergistic effects could be important with the combination of several mycotoxins. Investigations in this direction are underway, together with isolation and characterization of the fungal species involved.     

Toxicity profile of commercially produced indigenous banana beer

Mycotoxins, together with endotoxins, represent important classes of naturally occurring contaminants in food products, posing significant health risks to consumers. The aim of this study is to investigate the occurrence of both Fusarium mycotoxins and endotoxins in commercially produced traditional banana beer. Two brands of commercially produced traditional banana beer were collected from a local retail market in Kigali, Rwanda. Beer samples were analysed for the presence of deoxynivalenol (DON), fumonisin B₁ and zearalenone (ZEA), using an enzyme-linked immuno-sorbent assay (ELISA) method. The quantification of bacterial endotoxin using Limulus amoeboecyte lysate (LAL) assay was also conducted. The contamination levels were 20 and 6.7?µg?kg^?1 for DON; 34 and 31.3?µg?kg^?1 for FB₁; 0.66 and 2.2?µg?kg^?1 for ZEA in brands A and B of the beers, respectively. Results indicate that the levels of Fusarium toxins and bacterial endotoxin reported in this study did not pose adverse human health effects as a result of drinking/consuming banana beer. However, exposure to low/sub-threshold doses or non-toxic levels of endotoxins magnifies the toxic effect of xenobiotic agents (e.g. fungal toxins) on liver and other target organs. Considering Fusarium toxins and/or endotoxin contamination levels in other agricultural commodities intended for human consumption, health risks might be high and the condition is aggravated when beer is contaminated by mixtures of the mycotoxins, as indicated in this study.     

Co-occurrence of aflatoxins B 1 , B 2 , G 1 , G 2 , zearalenone and fumonisin B 1 in Brazilian corn

Two hundred and fourteen unprocessed corn samples (1997-98 harvest), collected at wholesale markets in different regions in Brazil, were surveyed for the occurrence of mycotoxins. The samples were analysed for aflatoxins B 1 , B 2 , G 1 , G 2 , zearalenone and fumoni1sin B 1 using in-house validated methods. The occurrence of aflatoxin B 1 , zearalenone and fumonisin B 1 was found in 38.3, 30.4 and 99.1% of the samples, respectively. Aflatoxin B 1 , zearalenone and fumonisin B 1 contamination levels varied from 0.2 to 129, 36.8 to 719, and 200 to 6100 μg/kg, respectively. The cooccurrence of the two carcinogenic mycotoxins aflatoxin B 1 and fumonisin B 1 was observed in 100% of the aflatoxin-contaminated samples (82 samples). Cooccurrences of aflatoxin B 1 : zearalenone: fumonisin B 1 and aflatoxin B 1 : aflatoxin B 2 : fumonisin B 1 were found in 18 and 43 samples, respectively.     

超高效液相色谱-串联质谱法同时测定玉米中9种真菌毒素

为高效检测玉米中的生物毒素,采用80%乙腈?0.1%甲酸水溶液提取、QuEChERS法净化、甲醇?0.1%甲酸+5 mmol/L甲酸铵水溶液经C₁₈柱梯度洗脱分离、电喷雾正负离子同时扫描并多反应监测模式采集数据的综合方法,对玉米中黄曲霉毒素B₁、B₂、伏马毒素B₁、B₂、B₃、呕吐毒素、3-乙酰脱氧雪腐镰刀菌烯醇、15-乙酰脱氧雪腐镰刀菌烯醇及玉米赤霉烯酮9种真菌毒素进行同时测定。结果表明,9种真菌毒素在0.25～250 μg/L浓度范围内线性关系良好,相关系数均在0.9999以上,检出限在0.079～1.8 μg/kg之间,定量限在0.26～6.0 μg/kg之间,回收率在80.2%～113.8%之间,相对标准偏差≤7.7%。用该方法同时检测吉林省240份玉米样品中9种真菌毒素,其中未检测出黄曲霉毒素B₁、B₂,但其它7种毒素均有检出,其中ZEN检出率最小,为14.6%,FB₂检出率最大,达到98.3%。本方法操作简单、灵敏度高、重现性好,结果准确,适用于玉米中多组分真菌毒素同时检测。     

Simultaneous determination of 10 mycotoxins in grain by ultra-high-performance liquid chromatography–tandem mass spectrometry using 13C15-deoxynivalenol as internal standard

An ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method for simultaneous determination of 10 mycotoxins in grain was developed. The selected mycotoxins were: deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, fusarenon X, moniliformin, zearalenone, zearalanone, ochratoxin A and ochratoxin B. The samples were extracted with aqueous acetonitrile (84?:?16,?v/v) and purified by reliable laboratory-made mixed cartridges. The analytes were separated on an Acquity UPLC HSS T3 column (100?×?2.1?mm,?1.8?µm) and eluted with a mobile phase of water containing 0.2% aqueous ammonia and acetonitrile/methanol (90?:?10,?v/v). All mycotoxins were detected with a Waters Micromass Quattro Ultima Pt tandem quadrupole mass spectrometer operating in negative electrospray ionization using multiple reaction monitoring mode. Accurate determination was achieved by employing commercial ¹³C₁₅-deoxynivalenol as internal standard, which compensated for target loss and eliminated matrix effects. The established method was further validated by determining the linearity (R ^2?>?0.9990), average recovery (75.8–106.5%), sensitivity (limit of quantitation 0.09–8.48?µg?kg^?1) and precision (relative standard deviation?≤?6.9%). It was shown to be a suitable method for simultaneous determination of 10 mycotoxins in grain. Finally, a total of 69 corn samples randomly collected from eastern and northern China were analyzed. The results showed that deoxynivalenol was the most frequently detected contaminant, whilst 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, zearalenone, zearalanone, fusarenon X and moniliformin also occurred frequently. Ochratoxin A and ochratoxin B were present only in trace amounts in a small number of samples.     

Evaluation of enniatins A,A1, B,B1 and beauvericin in Portuguese cereal-based foods

Sixty-one samples of Portuguese cereal-based foods were analysed for the occurrence of emerging mycotoxins called enniatins (A, A1, B and B1) and beauvericin. Samples were extracted with a mixture of acetonitrile/water (85/15, v/v) using an Ultra-Turrax homogeniser, and mycotoxins were detected with liquid chromatography coupled to a mass spectrometer. This method was validated and adequate values of recovery (70–103%) and relative standard deviation (<15%) were obtained. Signal suppression/enhancement was studied and matrix-matched calibration used to minimise this effect, but no additional clean-up step was necessary. The mass spectrometer was operated in selected reaction monitoring (SRM) mode and with selected transitions for each compound to quantify and to qualify them. Fifty-nine per cent of samples were contaminated. The percentages of enniatins were 53%, 49%, 44% and 16% for A1, B, B1, and A, respectively, and for beauvericin it was 1.6%. For the total samples, the mean contamination was 30, 24, 15, 2.1 and 0.1?ng?g^?1 for enniatins A1, B, B1 and A, and beauvericin, respectively. The wheat-based samples showed higher levels and greater prevalence than any other cereals monitored. These results were used to estimate the daily intake of ENs from wheat-based cereal by the Portuguese population. At the same time, the usefulness of this method in the analysis of other important mycotoxins (aflatoxin B₁, ochratoxin A, deoxynivalenol, T-2 toxin, fumonisin B₁ and zearalenone) was evaluated.     

A sub‐Saharan African perspective on mycotoxins in beer – a review

Beer is an alcoholic beverage made from a cereal grain extract and is widely consumed in sub‐Saharan Africa and the world at large. However, beer consumption could expose consumers to mycotoxins. In this review, we appraised the different mycotoxins associated with beer contamination, elucidating their structures and incidence in cereals involved in beer production. The common mycotoxins that are found within the brewing process are reviewed. These include aflatoxin B₁ (AFB₁), fumonisin (FB), ochratoxin A (OTA), zearalenone (ZEA) and deoxynivalenol (DON), which are the prime contaminants in beer produced in sub‐Saharan Africa. Residual levels of <20% of AFB₁, OTA and FB₂ together with the transformation of ZEA (into a less toxic compound β‐zearalenol) can be achieved during the production of beers originating from Europe/America, while >50% of DON and higher ratios of FB₁ can be recovered in finished beer. Adsorption is the major means of mycotoxin removal during beer production. In contrast, traditional African beer processes show no significant efficient removal of mycotoxins. This is because the prevailing environmental conditions during beer production are favourable to mycotoxigenic fungal proliferation. This subsequently leads to relatively high concentration of mycotoxins in freshly processed beer, with a possible increase during the beer shelf‐life owing to the absence of appropriate microbial stabilisation treatments in the finished processed beer. © 2019 The Institute of Brewing & Distilling     

Simple and high-throughput method for the multimycotoxin analysis in cereals and related foods by ultra-high performance liquid chromatography/tandem mass spectrometry

A rapid, reliable and sensitive method was developed to determine 12 mycotoxins (deoxynivalenol, aflatoxins B1, B2, G1, G2 and M1, fumonisins B1 and B2, ochratoxin A, HT-2 and T-2 toxin and zearalenone) simultaneously in maize, walnuts, biscuits and breakfast cereals. The method is based on a single extraction step using acetonitrile/water mixture (80/20 v/v) followed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS). The selectivity of the MS/MS detection allowed the elimination of further clean up steps. Extraction, chromatographic and detection conditions were optimised in order to increase sample throughput and sensitivity. Matrix-matched calibration was used for quantification and recoveries of the extraction process ranged from 70.0% and 108.4%, with relative standard deviations lower than 25% in all the cases, when samples were fortified at 5 and 50 μg/kg. Limits of detection ranged from 0.01 to 2.1 μg/kg and limits of quantification ranged from 0.03 to 6.30 μg/kg, which were always below the tolerance levels of mycotoxins set by European Union in the matrices evaluated. Several samples were analysed and aflatoxins B1, B2, G1, G2 and T-2 toxin were detected in one maize sample, with concentrations lower than 6.0 μg/kg and deoxynivalenol was detected in a breakfast cereal at 42.1 μg/kg.     

Survey of the mycobiota of Spanish malting barley and evaluation of the mycotoxin producing potential of species of Alternaria, Aspergillus and Fusarium

The present work deals with the toxigenic mycobiota occurring in Spanish malting barley and the capability for producing mycotoxins by several important toxigenic fungi. One hundred and eighty seven samples of malting barley were gathered from Spanish breweries before processing. One hundred and fifty kernels per sample were surface-sanitized with a 2% sodium hypochlorite solution and incubated on three culture media. The most abundant fungi were species of Alternaria, Aspergillus, Penicillium and Fusarium, which were present in 93%, 82.3%, 57.8% and 27.8% of the samples, respectively. To evaluate their mycotoxin producing potential a number of isolates belonging to each genus, except Penicillium, were randomly selected and incubated on culture media known to be appropriate for production of mycotoxins. Alternariol and alternariol monomethyl ether were produced by 26.7% of Alternaria spp. isolates (all belonged to Alternaria alternata). All tested isolates of F. verticillioides produced fumonisin B(1) (FB(1)) and 61.3% of them produced fumonisin B(2) (FB(2)), whereas FB(1) was synthesized by 83.3% and FB(2) by 77.8% of F. proliferatum isolates. Twenty percent of the isolates of the Aspergillus flavus/A. parasiticus group had the capability to produce aflatoxin B(1) and aflatoxin B(2). Thirty out of 34 isolates of F. graminearum produced deoxynivalenol and zearalenone whereas the other 4 isolates produced nivalenol. Ochratoxin A was detected in 75% and 15% of isolates of Aspergillus section Nigri and A. ochraceus, respectively. This is the first survey carried out in Spain on the toxigenic mycobiota contaminating malting barley in breweries and the mycotoxin producing capacity of several species. The information obtained is useful for assessing the risk of mycotoxins in beer.     

固相萃取柱净化-超高效液相色谱-串联质谱法快速测定液态乳中14 种真菌毒素

建立使用固相萃取柱净化液态乳中14 种真菌毒素（黄曲霉毒素B1、黄曲霉毒素B2、黄曲霉毒素G1、黄曲霉毒素G2、黄曲霉毒素M1、赭曲霉毒素A、橘霉素、T-2毒素、杂色曲霉素、伏马毒素B1、伏马毒素B2、玉米赤霉烯酮、脱氧雪腐镰刀菌烯醇、青霉酸）多残留的超高效液相色谱-串联质谱检测方法。样品经含0.1%甲酸-乙腈沉淀蛋白和提取,固相萃取柱Oasis PRiME HLB净化后,以0.1%甲酸溶液与乙腈为流动相,经ACQUITY UPLC HSS T3色谱柱（2.1?mm×100?mm,1.8?μm）分离,梯度洗脱,采用电喷雾-正离子多反应监测模式,外标法定量。结果表明：14?种真菌毒素的定量限（RSN≥10）为0.5～5?μg/kg,高、中、低3?个添加水平时,平均回收率为67.7%～112.7%,相对标准偏差为0.43%～7.28%。该方法的检测速度快,净化效果较好,基质干扰较少,灵敏度高,结果准确、可靠,可用于液态乳中真菌毒素的检测分析。     

Simultaneous determination of 10 mycotoxins in grain by ultra-high-performance liquid chromatography-tandem mass spectrometry using ¹³C₁₅-deoxynivalenol as internal standard

An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of 10 mycotoxins in grain was developed. The selected mycotoxins were: deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, fusarenon X, moniliformin, zearalenone, zearalanone, ochratoxin A and ochratoxin B. The samples were extracted with aqueous acetonitrile (84 : 16, v/v) and purified by reliable laboratory-made mixed cartridges. The analytes were separated on an Acquity UPLC HSS T3 column (100 × 2.1 mm, 1.8 μm) and eluted with a mobile phase of water containing 0.2% aqueous ammonia and acetonitrile/methanol (90 : 10, v/v). All mycotoxins were detected with a Waters Micromass Quattro Ultima Pt tandem quadrupole mass spectrometer operating in negative electrospray ionization using multiple reaction monitoring mode. Accurate determination was achieved by employing commercial 13C??-deoxynivalenol as internal standard, which compensated for target loss and eliminated matrix effects. The established method was further validated by determining the linearity (R2 > 0.9990), average recovery (75.8-106.5%), sensitivity (limit of quantitation 0.09-8.48 μg kg?1) and precision (relative standard deviation ≤ 6.9%). It was shown to be a suitable method for simultaneous determination of 10 mycotoxins in grain. Finally, a total of 69 corn samples randomly collected from eastern and northern China were analyzed. The results showed that deoxynivalenol was the most frequently detected contaminant, whilst 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, zearalenone, zearalanone, fusarenon X and moniliformin also occurred frequently. Ochratoxin A and ochratoxin B were present only in trace amounts in a small number of samples.     

Development of a multicomponent method for Fusarium toxins using LC-MS/MS and its application during a survey for the content of T-2 toxin and deoxynivalenol in various feed and food samples.

A reliable, sensitive and selective method was developed to determine different Fusarium mycotoxins (trichothecenes Type A and B, zearalenone) simultaneously in cereals and cereal-based samples using liquid chromatography with tandem mass spectrometry (LC-ESI-MS/MS). Sample preparation is based on a standard solvent extraction step followed by two different kinds of solid-phase clean-up procedures: using a multifunctional MycoSep material for trichothecenes and zearalenone. The average recoveries for trichothecenes ranged from 65% for nivalenol (NIV) up to 96% for deoxynivalenol (DON) and 89% for zearalenone (ZON). The limit of quantification varied between 0.02 and 10 ppb for each substance. In addition, a screening survey with 685 samples was carried out to compare contents of T-2 toxin and deoxynivalenol and to investigate potential coherence in contamination pattern.     

Validation of a UHPLC-FLD method for the simultaneous quantification of aflatoxins,ochratoxin A and zearalenone in barley

A fast and simple UHPLC-FLD method has been developed for the simultaneous determination in barley of aflatoxins (B1, G1, B2 and G2), ochratoxin A (OTA) and zearalenone (ZEA), some of the most important mycotoxins due to their toxicity and occurrence. The procedure is based on the extraction of the six mycotoxins with a mixture of acetonitrile and water, and the purification of the extract with immunoaffinity columns before analysis. Detection of AFB1 and AFG1 is improved using a photochemical reaction. The method has been validated with satisfactory results. Limits of detection were 340 ng kg⁻¹ for ZEA, 13 ng kg⁻¹ for OTA and varied from 0.5 to 15 ng kg⁻¹ for aflatoxins. Recovery percentages were between 78.2% and 109.2%. After being validated, the method has been successfully applied to 20 barley samples cultivated in a region of northern Spain (Navarra).     

Determination of mycotoxins in cereals by liquid chromatography tandem mass spectrometry

A liquid chromatography tandem mass spectrometry (LC–MS/MS) method is described for simultaneous determination of aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB₁ and FB₂), T2 and HT2-toxin in cereals. One-step extraction using solvent mixtures of acetonitrile:water:acetic acid (79:20:1) without any clean-up was employed for extraction of these mycotoxins from cereals. The mean recoveries of mycotoxins in spiked cereals ranged from 76.8% to 108.4%. Limits of detection (LOD) and quantification (LOQ) ranged 0.01–20 and 0.02–40 ng/g, respectively. The developed method has been applied for the determination of mycotoxins in 100 cereal samples collected from Malaysian markets. A total of 77 cereal samples (77%) contaminated with at least one of these mycotoxins. Occurrence of mycotoxins in commercial cereal samples were 70%, 40%, 25%, 36%, 19%, 13%, 16, and 16% for aflatoxins, OTA, ZEA, DON, FB₁, FB₂, T2 and HT2-toxin, respectively. The results demonstrated that the procedure was suitable for the determination of mycotoxins in cereals and could be implemented for the routine analysis.     

Co-occurrence of mycotoxins in commercial formula milk and cereal-based baby food on the Qatar market

The present study was conducted to explore the occurrence of mycotoxins in commercial baby foods in Doha-Qatar. LCMS/MS- and HPLC-based analysis of baby food (n = 67) for 12 mycotoxins confirmed the presence of aflatoxin M1 (AFM1, 33%), ochratoxin A (OTA, 31%), deoxynivalenol (DON, 27%), aflatoxin B1 (AFB1, 22%), fumonisin B2 (FB2, 10%), zearalenone (ZEN, 4%) and T-2 toxin (2%). Noodles exhibited the maximum contamination percentage, with 33% of the samples being contaminated above the EU maximum limits, for at least one mycotoxin. Among the multi-grain flake samples, up to 28% and for the milk and milk-based-cereal samples, 14% contained at least one mycotoxin above the EU maximum limits. From all cereal-based food samples, 22%, 5%, 2% and 2% were concurrently contaminated with 2, 3, 4 and 5 mycotoxins, respectively. The occurrence of toxicological important mycotoxins in Qatari market warrants the implementation of strict regulatory limits to protect human health.     

Sample preparation for photometric determination of histamine in foodstuffs compared with capillary electrophoresis

 To determine levels of histamine, two methods were used, photometry in conjunction with two sample clean-up procedures, and capillary zone electrophoresis (CZE). The two sample clean-up procedures used were liquid liquid extraction (LLE) with n-butanol and solid phase extraction (SPE). Using CZE, the separation of histamine from the matrix was good. The other method, photometry, represents a classic and simple method, that can be employed for in situ measurement of histamine. We found that it was necessary to clean up the samples prior to photometry; if this was not done, the recorded levels of histamine were higher than those determined by CZE. In order to determine levels of histamine, both of these rapid tests were applied to ten different foodstuffs. The levels of histamine measured using photometry following either LLE or SPE were compared. The results indicated that photometry is a suitable method for the measurement of histamine, although the sample solutions have to be purified by either LLE or SPE. Samples do not need to be cleaned up before CZE because there is no interference between histamine and attendant material. Both sample clean-up procedures were applied to the following foodstuffs: tomatoes, sauerkraut, tuna, leaf spinach, cream spinach, white wine and mackerel. The differences of the measured values vary between 3% and 18% for LLE and 6% and 27% for SPE. For the other foodstuffs, such as beef, beer and non-alcoholic beer, only one sample clean-up procedure is suitable. LLE used for beef and beer leads to differences in measured levels of histamine between 18% and 50%, respectively, whereas SPE used for non-alcoholic beer leads to differences of 20%. Received: 3 September 1997 / Revised version: 23 October 1997     

Sample preparation for photometric determination of histamine in foodstuffs compared with capillary electrophoresis

 To determine levels of histamine, two methods were used, photometry in conjunction with two sample clean-up procedures, and capillary zone electrophoresis (CZE). The two sample clean-up procedures used were liquid liquid extraction (LLE) with n-butanol and solid phase extraction (SPE). Using CZE, the separation of histamine from the matrix was good. The other method, photometry, represents a classic and simple method, that can be employed for in situ measurement of histamine. We found that it was necessary to clean up the samples prior to photometry; if this was not done, the recorded levels of histamine were higher than those determined by CZE. In order to determine levels of histamine, both of these rapid tests were applied to ten different foodstuffs. The levels of histamine measured using photometry following either LLE or SPE were compared. The results indicated that photometry is a suitable method for the measurement of histamine, although the sample solutions have to be purified by either LLE or SPE. Samples do not need to be cleaned up before CZE because there is no interference between histamine and attendant material. Both sample clean-up procedures were applied to the following foodstuffs: tomatoes, sauerkraut, tuna, leaf spinach, cream spinach, white wine and mackerel. The differences of the measured values vary between 3% and 18% for LLE and 6% and 27% for SPE. For the other foodstuffs, such as beef, beer and non-alcoholic beer, only one sample clean-up procedure is suitable. LLE used for beef and beer leads to differences in measured levels of histamine between 18% and 50%, respectively, whereas SPE used for non-alcoholic beer leads to differences of 20%. Received: 3 September 1997 / Revised version: 23 October 1997