Australian survey of acrylamide in carbohydrate-based foods

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

Determination of malachite green residues in rainbow trout muscle with liquid chromatography and liquid chromatography coupled with tandem mass spectrometry

A method for the determination of malachite green and its major metabolite leucomalachite green in rainbow trout muscle is reported with limits of detection of 0.8 and 0.6 μg kg^-1, respectively. Residues were extracted with an acetonitrile-acetate buffer mixture and partitioned into methylene chloride. Clean-up of the extracts was performed on alumina and propylsulfonic acid solid-phase extraction columns using the automated solid-phase extraction system. The chromatographic separation of malachite green and leucomalachite green was achieved on a Chromspher 5B column using an acetonitrile-acetate buffer mobile phase. Leucomalachite green was converted to malachite green by post-column oxidation before spectrophotometric detection at 600 nm. The mean recoveries of malachite green and leucomalachite green from control rainbow trout muscle spiked at 2-50 μg kg^-1 were 65% (range 63.4-65.9%, relative standard deviation 3.9-16.1%) and 74% (range 58.3-82.6%, relative standard deviation 3.3-11.4%), respectively. Qualitative confirmation of the determined residues was performed with liquid chromatography coupled with tandem mass spectrometry detection with limits of detection of 2.5 and 1 μg kg^-1 for malachite green and leucomalachite green, respectively.     

超高压液相色谱-串联质谱法测定虾中硝基呋喃代谢物

目的 建立虾中四种硝基呋喃代谢物的超高压液相色谱-串联四极杆质谱(UPLC-MS/MS)分析方法。方法 样品经2-NB衍生, HLB固相萃取柱净化、富集; 以乙腈?5 mmol/L乙酸铵(含0.1%乙酸)为流动相, 在正离子模式下, 采用多反应监测(MRM)方式进行检测。结果 四种硝基呋喃代谢物的定量限(LOQ)均为1.0 μg/kg, 三个添加水平(1.0、5.0、20.0 μg/kg)的平均回收率在81.6%~95.1%之间, 相对标准偏差均小于13.6%。结论 本方法适用于虾中污染物残留检测。     

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.     

Surveillance study of novobiocin and phenylbutazone residues in raw bovine milk using liquid chromatography-tandem mass spectrometry

A simple method permitting the simultaneous determination of trace residues of novobiocin and phenylbutazone in raw milk samples using liquid chromatography-tandem mass spectrometry was developed. Raw milk samples were mixed with acetonitrile to facilitate the concurrent precipitation of milk proteins and extraction of both veterinary drugs. Without additional clean-up or concentration of the resulting extract, the analytes could be quantified at concentrations as low as 0.0025 and 0.001 µg ml^?1 for phenylbutazone and novobiocin, respectively. The analysis of a series of fortified raw milk samples at analyte concentrations ranging from 0.005 to 0.1 µg ml^?1 and from 0.01 to 0.2 µg ml^?1 for phenylbutazone and novobiocin, respectively, yielded average recoveries ranging from 89.2% to 104.3% with standard deviations below 7%. The analytical method was applied to the analysis of raw milk samples collected from transport trucks upon delivery at dairy-processing plants throughout Alberta, Canada. Novobiocin was detected in 13 of 1072 samples tested at concentrations ranging from 0.001 to 0.007 µg ml^?1. Phenylbutazone was not detected in any of the samples tested.     

Antioxidant capacity of potato chips and snapshot trends in acrylamide content in potato chips and cereals on the Canadian market

The concentration of acrylamide was measured in selected varieties of five brands of potato chips and breakfast cereals over a 5-year period. Most of the products were purchased in one locality in Canada. Samples were analysed by an isotope dilution (¹³C₃) acrylamide method. They were extracted with water, partitioned with dichloromethane, filtered through a 5 kDa centrifuge filter, cleaned-up on HLB Oasis polymeric and Accucat mixed mode anion and cation exchange SPE columns, and analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The acrylamide concentration in potato chips varied from 106 to 4630 ng g^?1, while values in cereals varied from 50 to 347 ng g^?1. Wide variations were observed between brands, within brands over time, and between lots of the same brand. A subset of potato chip samples was analysed for in vitro antioxidant activity. No relationship was found between antioxidative capacity of potato chips and their acrylamide content.     

UNE-EN ISO/IEC 17025:2005-accredited method for the determination of pesticide residues in fruit and vegetable samples by LC-MS/MS

A rapid, simple and sensitive multi-residue method was developed and validated for the simultaneous quantification and confirmation of 69 pesticides in fruit and vegetables using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted following the quick, easy, cheap, effective, rugged and safe method known as QuEChERS. Mass spectrometric conditions were individually optimised for each analyte in order to achieve maximum sensitivity in multiple reaction monitoring (MRM) mode. Using the developed chromatographic conditions, 69 pesticides can be separated in less than 17 min. Two selected reaction monitoring (SRM) assays were used for each pesticide to obtain simultaneous quantification and identification in one run. With this method in SRM mode, more than 150 pesticides can be analysed and quantified, but their confirmation is not possible in all cases according to the European regulations on pesticide residues. Nine common representative matrices (zucchini, melon, cucumber, watermelon, tomato, garlic, eggplant, lettuce and pepper) were selected to investigate the effect of different matrices on recovery and precision. Mean recoveries ranged from 70% to 120%, with relative standard deviations (RSDs) lower than 20% for all the pesticides. The proposed method was applied to the analysis of more than 2000 vegetable samples from the extensive greenhouse cultivation in the province of Almería, Spain, during one year. The methodology combines the advantages of both QuEChERS and LC-MS/MS producing a very rapid, sensitive, accurate and reliable procedure that can be applied in routine analytical laboratories. The method was validated and accredited according to UNE-EN-ISO/IEC 17025:2005 international standard (accreditation number 278/LE1027).     

高效液相色谱-串联质谱法测定动物肌肉组织中氨基甲酸酯类杀虫剂及其代谢物残留

建立动物组织中氨基甲酸酯类杀虫剂及其代谢物(共16种)残留的高效液相色谱-串联质谱分析方法。样品经乙腈提取、浓缩、净化,液相色谱串联质谱测定,内标法定量。16种杀虫剂在1.0～100μg/L范围内线性关系良好(r＞0.9959);方法定量限为0.5～2.5μg/kg;样品添加5.0、10.0、20μg/kg时,加标回收率为71.4%～105.5%;相对标准偏差为3.2%～13.7%。该方法具有简便快捷、灵敏度高的特点,适用于动物肌肉中氨基甲酸酯类杀虫剂及其代谢物残留量的检测。     

沙棘粕醇提物的定性定量分析及其对衰老小鼠肝脏抗氧化指标的影响

利用沙棘粕为研究对象,经乙醇提取、大孔吸附树脂纯化获得沙棘粕醇提物（sea buckthorn seed extract,SBSE）。利用超高效液相色谱-串联四极杆飞行时间质谱（ultra-performance liquid chromatography coupled with quadruple time-of-flight tandem mass spectrometry,UPLC-QTOF-MS/MS）对SBSE进行定性研究,通过超高效液相色谱-串联三重四极杆质谱（ultra performance liquid chromatography coupled with triple quadruple mass spectrometry,UPLC-QQQ-MS）定量分析SBSE活性成分。最后研究分析SBSE对以D-半乳糖诱导的衰老小鼠的抗氧化功效,不同浓度SBSE灌胃衰老小鼠模型42 d后,比较小鼠肝脏组织中总抗氧化能力（total antioxidant capacity,T-AOC）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）、超氧化物歧化酶（superoxide dismutase,SOD）和过氧化氢酶（catalase,CAT）活性以及丙二醛（malondialdehyde,MDA）和脂褐素（lipofuscin,LP）水平。结果表明：通过UPLC-QTOF-MS/MS分析方法共鉴定出24?种化合物,其中与标准品比对共确认14?种物质;利用UPLC-QQQ-MS法,采用负离子多反应监测方式,建立SBSE的14?种化合物的定量分析方法,通过检测分析,SBSE中山柰酚及其衍生物所占比例最大,质量浓度为（667.94±5.61）μg/mL;其次为槲皮素及其衍生物（（204.01±0.04）μg/mL）,原花青素类物质为（33.97±0.49）μg/mL。经过42?d的衰老小鼠灌胃实验,与模型组相比,灌胃一定剂量SBSE可以提高小鼠肝脏组织中GSH-Px、SOD和CAT的活力;低剂量组小鼠肝脏组织中的T-AOC水平极显著高于模型组（P＜0.01）;3?种灌胃剂量小鼠的肝脏组织LP和MDA含量均极显著低于模型组（P＜0.01）。     

Kinetics of semicarbazide and nitrofurazone in chicken eggs and egg powders

The accumulation, depletion and partitioning of semicarbazide (SEM) and its parent compound nitrofurazone (NFZ) in eggs were studied using hens fed NFZ at therapeutic and sub-therapeutic levels. Dietary NFZ correlated strongly with NFZ and total SEM in eggs, while 28% of observed SEM was present in the form of parent NFZ. Depletion half-life in eggs was 2.4 days for SEM and 1.1 days for NFZ. NFZ accumulated preferentially in yolk (57–63%) as opposed to albumen, while 71–80% of SEM was found in yolk. In whole egg, 29% of SEM was present as tissue-bound residues compared with 80% in breast muscle. Whilst NFZ and SEM were partly degraded by pasteurization and spray drying, sufficient NFZ remained to suggest it might be detectable in egg powders when SEM is observed at low µg kg^?1 concentrations. NFZ was detectable in whole eggs during ingestion of only 0.1% of the therapeutic NFZ dose, making detection of intact NFZ in eggs a feasible means to prove conclusively the administration of this banned compound.     

高效液相色谱-串联质谱测定香辛料中的去甲乌药碱

建立了高效液相色谱-串联质谱(HPLC-MS/MS)快速测定香辛料中去甲乌药碱的分析方法。实验优化了样品前处理条件和色谱质谱条件。在优化条件下,样品经体积比为80%甲醇-水提取,纯水进行一定倍数的稀释,以Waters XBridge C18(150 mm×2.1mm,5μm)色谱柱分离,电喷雾正离子扫描,多反应监测(MRM)模式检测,基质匹配标准溶液外标法定量,实现了香辛料中去甲乌药碱的精确定量分析。去甲乌药碱在0.05~20.0 ng/mL范围内线性关系良好,相关系数为0.9999,方法检出限为0.7μg/kg,定量限为2.33μg/kg,在3个添加水平条件下八角的平均回收率为91.80%~99.97%,相对标准偏差为1.43%~2.35%。该方法简单、灵敏、准确性高、稳定性好,适用于香辛料中去甲乌药碱的测定。     

Mycotoxin profiles in the grain of Triticum monococcum,Triticum dicoccum and Triticum spelta after head infection with Fusarium culmorum

BACKGROUND: The aim of study was to investigate mycotoxin profiles in the grain of spring lines of Triticum monococcum (12 lines), T. dicoccum (13 lines) and T. spelta (five lines), in comparison to the T. aestivum cultivar Sumai‐3 which is resistant to Fusarium head blight. The grain was obtained from control heads and heads artificially inoculated in the field with Fusarium culmorum. Mycotoxins were determined by LC‐MS/MS. RESULTS: A total of 11 toxins were identified in control grain samples. Deoxynivalenol (DON) concentrations exceeded 0.5 mg kg^?1 in only three samples of T. monococcum grain and in one sample of T. dicoccum grain. Inoculation with F. culmorum resulted in a substantial increase in the concentrations of DON (to 63 mg kg^?1) in the T. monococcum and DON‐3‐glucoside (to 5.6 mg kg^?1) in the T. dicoccum. Inoculation contributed to a drop in tentoxin levels (by 57% in T. spelta) and to an increase of cyclodepsipeptide concentrations (in particular enniatins B and B₁) being two‐fold (T. monococcum) to four‐fold (T. dicoccum) higher on average than in control samples. The Sumai‐3 responded to inoculation with nearly a two‐fold drop in the levels of the cyclodepsipeptides. CONCLUSION: The results of a discriminant analysis for all identified toxins indicate that einkorn, emmer and spelt differ significantly with regard to the mycotoxin profiles of their grain. Copyright © 2009 Society of Chemical Industry     

Determination of quinolone residues in tilapias (Orechromis niloticus) by HPLC-FLD and LC-MS/MS QToF

A method for the simultaneous determination of flumequine, oxolinic acid, sarafloxacin, danofloxacin, enrofloxacin, and ciprofloxacin in tilapia (Orechromis niloticus) fillet, using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) is presented. The quinolones were extracted from the food matrix with a solution of 10% trichloroacetic acid and methanol (80:20 v/v). Clean-up of the extract was performed using polymeric solid-phase extraction cartridges. Identification of the quinolones was confirmed by liquid chromatography-tandem mass spectrometry. The HPLC-FLD method was validated in-house and the following analytical parameters were obtained: linearity higher than 0.99 for all the quinolones; intra- and inter-assay precisions were lower than 3.5% and 10.9%, respectively; and recoveries ranged from 73% to 110%. The limit of quantification was below the maximum residue limit established by the Joint Expert Committee on Food Additives (JECFA), which indicates that the method is appropriate for the determination of quinolones in fish fillet.     

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.     

养殖水产品中孔雀石绿、结晶紫及其代谢产物的前处理方法研究

根据SN/T 1768-2006、GB/T 19857-2005、GB/T 20361-2006标准,比较适合以上标准的3种水产品前处理方法,即:固相萃取法、旋转蒸发法、氮气吹干法.采用液相色谱串联质谱(LC-MS)检测水产品中孔雀石绿(MG)、结晶紫(CV)含量.以3种前处理方法所得回收率为指标,确定固相萃取法为适合的方法.换用不同的固相萃取小柱,对固相萃取法进行优化,以获得最大回收率.结果表明固相萃取小柱LH的最佳回收率超过88％,该固相小柱的重复使用回收率损失仅3％.该方法简便、快速、灵敏,适于水产品中孔雀石绿及其代谢物隐色孔雀石绿,结晶紫及其代谢物隐色结晶紫残留量的检测.     

HPLC-MS/MS测定玉米中异恶唑草酮及代谢物残留量

建立玉米中异恶唑草酮及代谢物残留量同时测定的高效液相色谱-串联质谱(high performance liquid chromatorgerphy-mass spectrometry/mass spectrometry,HPLC-MS/MS)分析法。试样用乙酸-乙腈(1:99, V/V)高速匀浆提取、醋酸钠和无水硫酸镁盐析后,提取液经N-丙基乙二胺(PSA)、十八烷基硅烷(ODS)和石墨化炭黑(GCB)净化,除去样品中脂肪和色素等大多数的干扰基质,用高效液相色谱-串联质谱仪检测,外标法定量。异恶唑草酮及代谢物的添加量在0.005～0.100mg/kg范围内,样品平均加标回收率在74.8%～107.2%之间,相对标准偏差为6.45%～11.15%;方法的检测限异恶唑草酮为0.01mg/kg、异恶唑草酮代谢物0.005mg/kg。本方法灵敏、准确、省时和操作简便,适用于玉米中异恶唑草酮及代谢物残留量同时检测和确证。     

Development of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of glucocorticoid residues in edible tissues of swine,cattle, sheep,and chicken

A confirmatory and quantitative method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine the presence of eight glucocorticoids (prednisone, prednisolone, hydrocortisone, methylprednisolone, dexamethasone, betamethasone, beclomethasone, and fludrocortisone) in the muscles and livers of swine, cattle, and sheep and the muscle of chicken is described. After deconjugation in alkali media, samples were extracted with ethyl acetate for glucocorticoids followed by solid-phase extraction clean-up and reconstitution in the LC mobile phase. The hydrolysis procedure with sodium hydroxide was used to reduce handling time. A single-step solid-phase extraction method was optimized which is suitable for the clean-up of the compounds of interest in many diverse tissue matrices. LC separations were performed on a C₁₈ column with gradient elution using acetonitrile and water (containing 0.2% formic acid) and the two epimers betamethasone and dexamethasone were successfully separated. LC-electrospray ionization (ESI)-MS/MS in negative mode with selected reaction monitoring (SRM) mode was performed to improve method sensitivity and reduce matrix interference. Two SRM transitions were used for each compound. The recovery of glucocorticoids spiked at levels of 0.5–16 µg kg^?1 ranged from 55% to 107%; the between-day relative standard deviations were no more than 15%. The limits of quantification were 0.5–2.0 µg kg^?1 in muscle and 1–4 µg kg^?1 in liver. The optimized procedure was successfully applied to monitor the food at the 2008 Summer Olympics Games in Beijing, China, demonstrating the method to be simple, fast, robust, and suitable for identification and quantification of glucocorticoids residues in foods of animal origin.     

Determination of acrylamide in foods by pressurized fluid extraction and liquid chromatography-tandem mass spectrometry used for a survey of Spanish cereal-based foods

An automated and rapid method for the determination of acrylamide in different food products is presented. The method involves pressurized fluid extraction (PFE) of foods with acetonitrile and precipitation with Carrez reagents. The final extract is analysed by liquid chromatography coupled to electrospray ionization tandem mass spectrometry (ESI-MS-MS). The main parameters affecting the performance of ESI-MS-MS and PFE were optimized using a design of experiments approach. The limit of quantification of the method was 5 µg kg^-1, and recoveries from incurred samples ranged between 93 and 101%. The accuracy was evaluated using the reference test materials FAPAS T3002, T3005 and T3011. Using the optimized method, 62 food samples of potato chips, snacks, biscuits, breakfast cereals and crisp bread sampled from Valencia, Spain, supermarkets were surveyed for acrylamide levels. The levels were similar to those reported in the European Union and USA.     

Distribution of diarrhetic shellfish poisoning toxins in consignments of blue mussel

Data describing the distribution of diarrhetic shellfish poisoning toxins in 13 consignments of Danish-produced blue mussels are reported. The content of diarrhetic shellfish poisoning toxins was measured by a liquid chromatography coupled with tandem mass spectrometry detection method, and mean levels in the 13 consignments varied from 58 to 243 μg kg^-1. The distributions of diarrhetic shellfish poisoning toxins in the consignments were relatively homogenous as the relative standard deviation of the content varied from 7 to 19%. The results are discussed in relation to food safety, the uncertainty of sampling and analysis, and the newly introduced European Union maximum levels of marine biotoxins in seafood products.     

Detection of adulteration of anti-hypertension dietary supplements and traditional Chinese medicines with synthetic drugs using LC/MS

A sensitive and specific liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) method was developed for the analysis of 18 drugs used for the treatment of anti-hypertension, including diuretics, calcium antagonists, and angiogenesis-converting enzyme inhibitors (ACEI) as adulterants in dietary supplements and traditional Chinese medicines. Separation was accomplished on a Xtimate? C₁₈ reversed-phase column using a mixture of methanol, acetonitrile and 20 mM ammonium formate buffer (pH 3.2) as mobile phase. The method demonstrated linearity from 0.03 to 21.52 mg kg^?1. Limits of detection ranged from 6.5 to 86.0 µg kg^?1. The recoveries of spiked samples ranged from 71% to 109%. The procedure was successfully applied in routine inspection analysis.