Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods.

Acrylamide concentrations in processed foods (63 samples covering 31 product types) from Japan were analysed by LC-MS/MS and GC-MS methods. The limit of detection and limit of quantification of acrylamide were 0.2 ng x ml(-1) (6 fmol) and 0.8 ng x ml(-1) (22 fmol), respectively, by LC-MS/MS, and those of 2,3-dibromopropionamide derived from acrylamide were 12 ng x ml(-1) (52 fmol) and 40 ng x ml(-1) (170 fmol), respectively, by GC-MS. Repeatability given as RSD was <5 and <15% for the LC-MS/MS and GC-MS methods, respectively. High correlation (r(2) - 0.946) was observed between values obtained by the two methods. Most potato crisps and whole potato-based fried snacks showed acrylamide concentrations >1000 microg x kg(-1). The concentrations in non-whole potato-based snacks, rice crackers processed by grilling or frying, and candied sweet potatoes were lower compared with those in the potato crisps and the whole potato-based fried snacks. One of the whole potato-based fried snacks, however, showed low acrylamide concentration (<50 microg x kg(-1)) suggesting the formation of acrylamide is strongly influenced by processing conditions. Acrylamide concentrations in instant precooked noodles and won-tons were <100 microg x kg(-1) with only one exception. Roasted barley grains for 'Mugi-cha' tea contained 200-600 microg x kg(-1) acrylamide.     

Determination of acrylamide in processed foods by LC/MS using column switching

An LC/MS method was developed for the determination of acrylamide (AA) in processed or cooked foods. AA was extracted with a mixture of water and acetone from homogenized food samples after the addition of 13C-labeled acrylamide (AA-1-(13)C) as an internal standard. The extract was concentrated, washed with dichloromethane for defatting, and cleaned up on Bond Elut C18, PSA and ACCUCAT cartridge-columns, and then AA was determined by LC/MS in the selected ion recording (SIR) mode. For the LC/MS analysis, four LC columns were connected in-line and the flow of the mobile phase was switched according to a time-program. Monitoring ions for AA were m/z 72 and 55, and those for AA-1-(13)C were m/z 73 and 56. AA and AA-1-(13)C were determined without interference from the matrices in all samples. The recoveries of AA from potato chips, corn snack, pretzel and roasted tea spiked at the level of 500 ng/g of AA were 99.5-101.0% with standard deviations (SD) in the range from 0.3 to 1.6%. The limits of detection and quantification of the developed method were 9 and 30 ng/g for AA in samples, respectively. The method was applied to the analysis of AA in various processed or cooked food samples purchased from retail markets. High levels of AA were found in potato chips and French-fried potato (467-3,544 ng/g). Fried and sugar-coated dough cakes (karinto) contained 374 and 1,895 ng/g. Corn snacks contained 117-535 ng/g of AA. Roasted foods (such as roasted sesame seed, roasted barley (mugi-cha), roasted tea (hoji-cha), coffee beans and curry powder) contained 116-567 ng/g of AA. Foods made from fish, egg and meat contained lower levels of AA than the plant-based foods. Foods containing much water showed a tendency to have low levels of AA compared with dry foods. The proposed method was applicable to the analysis of AA in variety of processed foods.     

An improved LC-MS/MS method for the quantitation of acrylamide in processed foods

An improved liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of acrylamide in processed foods. The homogenized samples, spiked with ¹³C₃-acrylamide as an internal standard, were extracted with water and centrifuged. D₅-3-chloropropanediol as a recovery standard was added to 1-ml aliquots, and the sample was purified with a C₁₈-cartridge column. The extract was directly analyzed using LC-MS/MS without derivatization. The ion transitions of 72–55 m/z (acrylamide), 75–58 m/z (¹³C₃-acrylamide), and 116–98 m/z (d₅-3-chloropropanediol) were found to be the most reliable for the identification and quantification of acrylamide in multiple reaction monitoring. The limit of quantification for acrylamide, defined as a signal-to-noise ratio of 10:1, was 2 μg/kg. The use of d₅-3-chloropropanediol minimized the effects of variation in the sample matrixes and increased the quality of analysis. This method could be applied to the quantification of acrylamide in processed foods.     

流动注射化学发光法快速测定油炸食品中的丙烯酰胺

为建立一种快速测定食品中痕量丙烯酰胺的灵敏准确、快速简便的新方法,以市售食品为样品,丙烯酰胺经提取后,利用其对鲁米诺—高锰酸钾化学发光体系的抑制作用,测定样品中的丙烯酰胺,并对体系的测定条件进行了优化。结果表明:丙烯酰胺测定的线性范围为1.0×10-10~1.0×10-4mol/L,相关系数r为0.9993,方法检出限为3.40×10-13mol/L,加标回收率为85.7%~98.2%,样品平行测定的相对标准偏差RSD为2.4%(n=9)。与气相色谱法对照测定,通过F检验和t检验表明,两种方法之间不存在显著性差异,结论的置信度为95%。该分析体系线性范围宽,灵敏度高,易实现自动化。具有简便快捷、成本低廉、实用性强、易于现场检测等优点,可用于食品中丙烯酰胺的测定。     

Application of ion-trap LC/MS/MS for determination of acrylamide in processed foods

Ion-trap LC/MS/MS was evaluated for use in the determination of acrylamide (AA) in processed foods. Multiple reaction monitoring (MRM) analysis of a series of AA standard solutions containing deuterium-labeled acrylamide (AA-d3) as an internal standard was performed. A linear relationship between the concentration of AA and the ratio of peak area (AA/AA-d3) in the extracted ion chromatogram (m/z 55, 58 derived from m/z 72, 75, respectively) was obtained over a wide range of 2-20,000 ng/mL. The quantification limit of AA was 2 ng/mL. In analyses of 37 commercial foods, AA was detected in a potato snack at the maximum value of 3,570 ng/g and found in 23 foods prepared or cooked at high temperature. The samples were analyzed in triplicate and the relative standard deviations (RSD) were less than 15% in many processed foods.     

高温加工食品中丙烯酰胺抑制技术研究进展

淀粉类食品在高温加工过程中产生丙烯酰胺的问题已引起世界各国的普遍关注。如何抑制其产生成为国际研究热点。本文简要综述了高温加工食品中阿烯酰胺形成机理，并重点讨论了影响丙烯酰胺产生的因素和抑制技术。     

高温加工食品丙烯酰胺抑制技术

淀粉类食品在高温加工过程中产生丙烯酰胺的问题已引起世界各国的普遍关注,如何抑制其产生成为国际研究热点。本文简要综述了高温加工食品中丙烯酰胺形成机理,并重点讨论了影响丙烯酰胺产生的因素和抑制技术。     

Study on rapid analysis method of pesticide contamination in processed foods by GC-MS and GC-FPD

A simple and rapid method using GC-MS and GC-FPD for the determination of pesticide contamination in processed food has been developed. Pesticides were extracted from a sample with ethyl acetate in the presence of anhydrous sodium sulfate, then cleaned up with a combination of mini-columns, such as macroporous diatomaceous earth, C18, GCB (graphite carbon black) and PSA. Recovery tests of 57 pesticides (known to be toxic or harmful) from ten kinds of processed foods (butter, cheese, corned beef, dried shrimp, frozen Chinese dumplings, grilled eels, instant noodles, kimchi, retort-packed curry and wine) were performed, and the recovery rates were mostly between 70% and 120%. This method can be used to judge whether or not processed foods are contaminated with pesticides at potentially harmful levels.     

Determination of acrylamide in processed foods by column-switching HPLC with UV detection

A simple and convenient analytical method for the determination of acrylamide in processed foods was established. Acrylamide was extracted with water in an ultrasonic bath. The extract was passed through an OASIS HLB cartridge and the eluate was injected into the HPLC system using a column-switching technique. The HPLC system consisted of two pumps, two 6-port-2-position valves, two columns and a UV detector. At first, the sample solution was chromatographed on an ODS column with a mobile phase of water, then the flow of the mobile phase was switched using a 6-port-2-position valve, and the acrylamide peak fraction was introduced into an aqueous gel permeation column (analytical column). The fraction was chromatographed again on the analytical column with a mobile phase of water, and the eluate was monitored with a UV detector (205 nm). The recoveries of acrylamide from potato chips, fried potato, croquette and instant noodle fortified at levels of 50 to 1,000 micrograms/kg were 93.1 to 101.5% and the coefficient of variation was 1.5 to 5.2%. The detection limit corresponded to 10 micrograms/kg in processed foods. Forty-six samples, potato chips (11), fried potato (10), croquette (20) and instant noodle (5), were analyzed by this method. The acrylamide level was 67-4,499 micrograms/kg for potato chips, 125-1,183 micrograms/kg for fried potato, nd-255 micrograms/kg for croquette and nd-151 micrograms/kg for instant noodle.     

Extraction and reliable determination of acrylamide from thermally processed foods using ionic liquid-based ultrasound-assisted selective microextraction combined with spectrophotometry

Acrylamide (AAm) is a carcinogenic chemical that can form in thermally processed foods by the Maillard reaction of glucose with asparagine. AAm can easily be formed especially in frequently consumed chips and cereal-based foods depending on processing conditions. Considering these properties of AAm, a new, simple and green method is proposed for the extraction of AAm from thermally processed food samples. In this study, an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF₄]) as extractant was used in the presence of a cationic phenazine group dye, 3,7-diamino-5-phenylphenazinium chloride (PSH⁺, phenosafranine) at pH 7.5 for the extraction of AAm as an ion-pair complex from selected samples. Under optimum conditions, the analytical features obtained for the proposed method were as follows; linear working range, the limits of detection (LOD, 3S_b/m) and quantification (LOQ, 10S_b/m), preconcentration factor, sensitivity enhancement factor, sample volume and recovery% were 2.2–350 µg kg^?1, 0.7 µg kg^?1, 2.3 µg kg^?1, 120, 95, 60 mL and 94.1–102.7%, respectively. The validity of the method was tested by analysis of two certified reference materials (CRMs) and intra-day and inter-day precision studies. Finally, the method was successfully applied to the determination of AAm levels in thermally processed foods using the standard addition method.     

油炸食品中丙烯酰胺分析方法研究进展

对食品中丙烯酰胺分析方法的研究进展进行了综述。主要包括GC-MS、LC-MS和LC-MS-MS方法分析食品中的丙烯酰胺以及一些国家机构规定的官方分析方法。另外,对现有分析方法的优缺点进行了评述,对食品中丙烯酰胺的分析方法进行了展望。     

GC-MS测定富含油脂类食品中氯丙醇的方法研究

建立了油脂类食品中氯丙醇含量的气相色谱-质谱法（GC-MS）联用技术检测方法,对油辣椒、腐乳、火锅底料以及鸡辣椒等食品中氯丙醇含量进行检测。结果表明：在10～500 μg/L范围内,3-氯-1,2-丙二醇（3-MCPD）的质量浓度与峰面积呈良好的线性关系,相关系数R2为0.999 5,方法检出限（LOD）为4.7 μg/kg,定量限（LOQ）为10.2 μg/kg,平均加标回收率在86.2%～108.5%,精密度试验测定得相对标准偏差（RSD,n=6）为4.26%。表明该方法准确、可靠、稳定,能够满足油脂类食品中氯丙醇含量的检测要求。     

食品中丙烯酰胺分析的样品前处理技术

近年来,关于食品中丙烯酰胺危害食品安全的问题倍受关注,在检测过程中,样品的前处理技术直接影响检测的效率和准确率。综述了近年来食品中丙烯酰胺分析的样品前处理技术,对加速溶剂萃取和固相微萃取等新技术进行了评述,并对食品中丙烯酰胺分析的前处理技术的发展方向进行了讨论。     

Determination of sucralose in foods by HPLC using pre-column derivatization

The development of a sensitive pre-column derivatization high-performance liquid chromatography (HPLC) method for determination of sucralose is reported. Sucralose is converted into a strongly ultraviolet (UV)-absorbing derivative, possessing strong absorption at 260 nm, by treatment with p-nitrobenzoyl chloride (PNBCl). Homogenized samples were dialyzed and washed with a Bond Elut ENV cartridge, then the eluate was evaporated to dryness and the residue was derivatized. Subsequently, the sucralose derivative was purified with hexane-ethyl actate (9:1) in a silica cartridge, and then the sucralose derivative was eluted with acetone. HPLC was performed on a phenyl column, using acetonitrile-water (73:27) as a mobile phase with UV detection (260 nm). The calibration curve was linear in the range of 1 microgram/mL to 50 micrograms/mL of sucralose. The recoveries of sucralose from eight kinds of foods spiked at the levels of 0.20 and 0.05 g/kg of sucralose were more than 76.2% with SD values in the range from 0.90% to 4.31%. The quantitative limit of the developed method was 0.005 g/kg for sucralose in samples.     

Interference-free determination of acrylamide in potato and cereal-based foods by a laboratory validated liquid chromatography–mass spectrometry method

A simple and rapid method was developed and validated for the determination of acrylamide in potato and cereal-based foods by using a single quadrupole liquid chromatography–mass spectrometry (LC–MS) interfaced with positive atmospheric pressure chemical ionization (APCI+). Acrylamide was simply extracted with 0.01 mM acetic acid in a vortex mixer prior to LC–MS analysis. The applicability of validated method was shown for a wide range of processed foods including chips, fries, crisps, breads, biscuits and cookies. The mean recovery was found to be 99.7 with a repeatability of 1.8% in the range 100–1000 ng/g. During LC–MS analyses, the major interfering co-extractive was identified as valine which yields characteristic [M + H]⁺ and compound specific product ions having m/z of 118 and 72, respectively. Valine increased the baseline signal preventing accurate and precise quantitation, and resulted in poorer sensitivity in selected ion monitoring mode. The adverse effect of valine could be limited by instrumentally adjusted delay time or by solid-phase extraction with strong cation-exchanger sorbent.     

A method for the determination of acrylamide in bakery products using ion trap LC-ESI-MS/MS

Acrylamide levels of bakery products, e. g., bread and bread rolls, are usually below 100 microg/kg , often even below 50 microg/kg. Therefore, usual analytical methods which have an LOQ greater, not dbl equals 25 microg/kg are not sensitive enough for detailed investigations on acrylamide formation within these commodities. An improved method for trace level determination of acrylamide in bakery products was developed using ion trap LC-ESI-MS/MS. Samples were divided into crumbs and crusts to achieve an initial concentration by removing the crumbs since these are devoid of acrylamide. After sample extraction and clean-up using multimode SPE cartridges, further analyte enrichment was accomplished by solid-phase-supported liquid-liquid extraction with ethyl acetate prior to LC-MS/MS analysis. The method was evaluated using bread, bread rolls, alkali-baked bread rolls, and toast. LOQ was calculated from the confidence interval of the calibration curve and found to be 1.7 ng/mL, corresponding to 17 microg/kg of product. When crumbs and crusts were separated, an LOQ of 10.2 microg/kg of bakery product could be obtained. As demonstrated in preliminary comparative analyses, accuracy of the method met the requirements for determination of trace level acrylamide formation in bakery products. Mean recovery was 102.4% (CV 4.5%), intermediate reproducibility revealed a CV of 2.1%, and a repeatability of CV 6.0%.     

A sensitive method for the determination of chlorine-36 in foods using accelerator mass spectrometry

A method using accelerator mass spectrometry (AMS) has been developed to offer a more sensitive alternative to scintillation techniques for the determination of chlorine-36 (³⁶Cl) in foods. The main problem in method development was the potential interference of the sulfur-36 (³⁶S) isobar. This was overcome by reducing the sulfur level of acid digests of food by precipitation of chloride as silver chloride, then purification by washing, dissolution and reprecipitation to present silver chloride as the AMS target. The limit of detection was around 0.1 Bq kg^?1 and the limit of quantitation was around 0.2 Bq kg^?1. The AMS method was only semi-quantitative at the lowest levels of interest. To test the method a few samples of milk (five) and blackberries (three) collected from near two nuclear power stations as potential sources of contamination were analysed. Blackberries spiked at 0.2 Bq kg^?1 and milk spiked at 0.1 Bq kg^?1 could be distinguished from method blanks. There was no ³⁶Cl detectable in the unspiked samples.     

Application of the standard addition method for the determination of acrylamide in heat-processed starchy foods by gas chromatography with electron capture detector

A gas chromatography electron capture detector (GC-ECD) using the standard addition method was developed for the determination of acrylamide in heat-processed foods. The method entails extraction of acrylamide with water, filtration, defatting with n-hexane, derivatization with hydrobromic acid and saturated bromine-water, and liquid–liquid extraction with ethyl acetate. The sample pretreatment required no SPE clean-up and concentration steps prior to injection. The final extract was analyzed by GC-ECD. The chromatographic analysis was performed on polar columns, e.g. Supelcowax-10 capillary column, and good retention and peak response of the analyte were achieved under the optimal conditions. The qualification of the analyte was by identifying the peak with same retention time as standard compound 2,3-DBPA and confirmed by GC–MS. GC–MS analysis confirmed that 2,3-DBPA was converted to 2-BPA nearly completely on the polar capillary column, whether or not treated with triethylamine. A four-point standard addition protocol was used to quantify acrylamide in food samples. The limit of detection (LOD) was estimated to be 0.6 μg/kg on the basis of ECD technique. Validation and quantification results demonstrated that the method should be regarded as a low-cost, convenient, and reliable alternative for conventional investigation of acrylamide.     

Validation and measurement uncertainty evaluation of the GC-MS method for the direct determination of hexamethylenetetramine from foods

A simple GC-MS method has been developed and validated for the direct determination of hexamethylenetetramine (HMT). The separation of HMT was performed using a MXT-1 column. The calibration curve was linear over the concentration range 0.1-25 μg/mL, with a good correlation coefficient (r =0.9996). The recoveries of HMT from foods spiked at 1, 5, and 10 μg/g ranged from 91.7% to 115.2%. Intra-day (n=5) and inter-day (n=5) precision were less than 7%. The limit of detection and the limit of quantification of the method were 0.05 and 0.15 μg/mL, respectively. The uncertainties associated with food matrix and calibration contributed most to the overall expanded uncertainty. The method validation data indicated that quantitative method could be applied to the direct determination of non-hydrolyzed HMT in foods.