柱前衍生化-气相色谱-质谱法定量测定食品中丙烯酰胺的含量

建立了气相色谱-质谱(GC-MS)定量测定食品中丙烯酰胺含量的分析方法。选择13C3-丙烯酰胺作为内标物。通过超纯水提取食品中的丙烯酰胺,经正己烷脱脂两次后,在酸性条件下选用溴化钾/溴酸钾为衍生剂进行衍生化反应,再采用乙酸乙酯进行液-液萃取两次,最后用三乙胺将丙烯酰胺转化为更稳定的产物2-溴丙烯酰胺,利用质谱检测器在选择离子扫描模式下测定2-溴丙烯酰胺。该方法在0.05～2.00 mg/kg范围具有良好的线性(r2=0.9995);检出限和定量限分别达到3 μg/kg和7 μg/kg;回收率范围为62.7%～65.5%。通过与前期建立的液相色谱-串联质谱(HPLC-MS/MS)方法进行对比,该法在薯片和面包样品中丙烯酰胺的检测结果略偏高,是一种可以用于常见食品中丙烯酰胺含量测定的分析方法。     

SPME/GC法测定油炸淀粉类食品中的丙烯酰胺

自制了十六醇/聚己二酸乙二醇酯(CA/PGA)固相微萃取探头,建立了油炸淀粉类食品中丙稀酰胺的SPME/GC测定方法。利用该方法测定了油炸方便面和油条中的丙烯酰胺。结果显示,SPME/GC法在2.5μg/kg~1500μg/kg范围内有很好的线性,检测限为2.5μg/kg,回收率为91.2%~98.8%,RSD为2.7%(n=6)。该法比传统的LLE溴衍生化/GC法灵敏度高,重现性好,操作简便。     

气相色谱-离子阱二级质谱测定食品中丙烯酰胺残留

建立了一种基于气相色谱-离子阱二级质谱(GC-MS/MS)检测食品(薯条,薯片,咖啡,饼干和膨化食品)中丙烯酰胺残留量的方法。样品中丙烯酰胺采用去离子水提取,正己烷脱脂后石墨化碳黑小柱净化,溴水衍生后GC-MS/MS进行分析。方法在10-1 000μg.L-1浓度范围内呈线性关系,相关系数为0.999,检出限为4.02μg.kg-1,在10,100,1 000μg.kg-1三个水平的相对标准偏差为8%-12%,回收率为68.3%-105.2%。结果表明,相对于GC-MS方法,GC-MS/MS分析时间短、无杂质峰干扰、灵敏度高,可以满足食品的丙烯酰胺检测大批量筛选要求。     

特丁基二甲基硅烷衍生化气相色谱-质谱联用法快速测定苹果汁中的棒曲霉素

运用特丁基二甲基硅烷(TBDMS)衍生化气相色谱-质谱(GC-MS)联用法快速、高灵敏地测定了苹果汁中的棒曲霉素(PAT)。样品用乙酸乙酯-正己烷提取,Carb/C18混合型固相萃取柱净化,TBDMS衍生,GC-MS测定,选择离子监测(SIM)模式,外标法定量。在0.01～1 mg/L的范围内线性良好(r＞0.98),在2～50 μg/kg的添加水平范围内,平均回收率为88%～98%,相对标准偏差(RSD)为5.3%～13.6%, PAT的检出限为0.5 μg/kg,测定低限为2 μg/kg。该方法快速、高灵敏、准确、专一、耐用,适合对苹果汁中PAT进行确证和定量测定。     

液相色谱-电喷雾质谱/质谱法测定高温烹制的淀粉类食品中的丙烯酰胺

以C18反相色谱柱为分析柱,以0.1%甲酸水溶液-甲醇(体积比为98∶2)为流动相,采用同位素稀释液相色谱-电喷雾 质谱/质谱(LC-MS/MS)技术对加热淀粉类食品中的丙烯酰胺进行了测定。利用Oasis HLB固相萃取柱对样品进行净化。方 法的线性范围为10～500 μg/L,线性相关系数为0.9995。方法的定性检出限为6 μg/kg,定量检出限为20 μg/kg。高 、中、低3个浓度水平的加标回收率为96.8%~97.4%,相对标准偏差小于10%。     

GC/MS测定锅巴中丙烯酰胺含量

建立了一种测定市售锅巴中的丙烯酰胺含量的方法.该法样品前处理不必经过溴化衍生,样品脱脂后用水提取丙烯酰胺,提取液过活性炭柱,再用乙酸乙酯将活性炭柱中吸附的丙烯酰胺洗脱.洗脱液浓缩后经气相色谱-质谱(GC-MS)定量分析,检测限为0.06 mg/kg,适合测定市售锅巴中的丙烯酰胺的含量.还考察了丙烯酰胺在水的固液两相中的分配比.     

衍生化气相色谱-质谱法测定玩具和食品接触材料中双酚A

建立了玩具和与食品接触的材料中双酚A的衍生化气相色谱-质谱(GC-MS)检测方法。通过索氏萃取富集样品中的双酚A,与乙酸酐反应,终产物用GC-MS进行测定。优化了衍生化时间、衍生化试剂用量等衍生化条件。在最佳条件下,双酚A衍生物稳定且峰形良好,在0.05～50 mg/L范围内,相关系数(r2)在0.999以上。在0.05、1.00、10.00 mg/kg 3个添加水平下,双酚A的加标回收率为80%～93%,相对标准偏差(RSD)均小于3.7%;检出限(以信噪比(S/N)=3计)为10 μg/kg。该方法精密度好、回收率高,可用于玩具和食品接触材料中双酚A的定量检测。     

化妆品中氯霉素的气相色谱-质谱快速分析

研究了用气相色谱-质谱分析化妆品中氯霉素(CAP)的方法.以乙酸乙酯作为提取溶剂,BSTFA TMCS(99 1)作为衍生化试剂,在70℃衍生化60min,用GC-MS(NCI)进行测定.方法的检出限为10 μg/kg,线性范围在0.5～500 ng/mL之间,在10、100、500 μg/kg 3个添加水平,方法回收率为94.4%～95.7%,相对标准偏差为0.23%～1.3%.方法操作快速简单,3 h可以完成整个样品分析.方法已用于化妆品中氯霉素的测定.     

气相色谱法测定食品中己二酸

建立了气相色谱/氢火焰离子化检测器同时测定6种食品中己二酸含量的方法.该方法通过加酸助溶,采用乙酸乙酯提取食品样品中的己二酸,浓缩后再用硅烷化试剂进行衍生化处理.考察了温度、时间及衍生化试剂用量对己二酸硅烷化衍生效果的影响.以庚二酸内标法定量测定,定量限为5 mg/kg,在5～600 μg/mL范围内呈良好线性关系,相...     

GC—MS-相转移衍生化法分析水相中亚硝酸根离子

采用相转移催化剂四辛基溴化铵及五氟苄基溴将水相(血、尿)中亚硝酸根离子衍生化生成可挥发性化合物,然后用GC-MS法进行测定.亚硝酸根离子含量在0.2～10 μg/ mL范围内与离子峰面积呈良好的线性关系,相关系数r=0.9998,检出限为0.1 μg / mL.用该方法对水、尿、血中亚硝酸根离子进行测定,测定结果的相对标准偏差为1.44%～4.17%(n=6),回收率为82%～84%.     

气相色谱-质谱法检测食品中的丙烯酰胺

建立了一种用于食品中丙烯酰胺含量的气相色谱-质谱联用检测方法。通过水和甲醇提取食品中的丙烯酰胺,经蛋白变性净化后用溴水对其进行加成衍生化,再采用有机溶剂进行液液萃取,之后同三乙胺发生定量反应转化为性质更稳定的产物后由气相色谱-质谱联用仪检测,同位素内标法定量。该方法在0.02,0.05和0.2 mg/kg等3个添加水平下面粉和面包中丙烯酰胺的回收率处于80%和110%之间,相对标准偏差（RSD）不大于12.7%;在0.04～4.00 mg/L内呈现良好的线性关系;灵敏度高,最低检测限达到5 μg/kg;选择性好,能有效消除复杂基质带来的干扰。可作为常见样品中丙烯酰胺含量检测的确证方法。     

Trace level determination of acrylamide in cereal-based foods by gas chromatography-mass spectrometry

A quantitative method has been developed for the determination of trace levels (<50 microg/kg) of acrylamide in cereal-based foods. The method is based on extraction of acrylamide with water, acidification and purification with Carrez I and II solutions, followed by bromination of the acrylamide double bond. The reaction product (2,3-dibromopropionamide) is extracted with ethyl acetate/hexane (4:1, v/v), dried over sodium sulfate, and cleaned up through a Florisil column. The derivative is then converted to 2-bromopropenamide by dehydrobromination with triethylamine and analyzed by gas chromatography coupled to mass spectrometry (GC-MS), employing (13C3)acrylamide as internal standard. In-house validation data for commercial and experimental cereal products showed good precision of the method, with repeatability and intermediate reproducibility relative standard deviations below 10%. The limit of detection and limit of quantitation are estimated at 2 and 5 microg/kg, respectively, and recoveries of acrylamide from samples spiked at levels of 5-500 microg/kg ranged between 93 and 104% after correction of analyte loss by the internal standard. Finally, a comparative test organized with two independent laboratories provided additional confidence in the good performance of the method, particularly at very low concentration levels.     

Rapid determination of acrylamide contaminant in conventional fried foods by gas chromatography with electron capture detector

Gas chromatography coupled with electron capture detector (GC-ECD) was successfully developed and applied for the rapid determination of acrylamide in conventional fried foods, such as potato crisps, potato chips, and fried chicken wings. The method included defatting with n-hexane, extraction with aqueous solution of sodium chloride (NaCl), derivatization with potassium bromate (KBrO3) and potassium bromide (KBr), and liquid-liquid extraction with ethyl acetate. The final acrylamide extract was analyzed by GC-ECD for quantification and by GC-MS for confirmation. The chromatographic analysis was performed on the HP-INNOWax capillary column, and good retention and peak response of acrylamide were achieved under the optimal conditions (numbers of theoretical plates N = 83,815). The limit of detection (LOD) was estimated to be 0.1 microg kg(-1) on the basis of ECD technique. Recoveries of acrylamide from conventional samples spiked at levels of 150, 500 and 1000 microg kg(-1) (n = 4 for each level) ranged between 87 and 97% with relative standard deviations (RSD) of less than 4%. Furthermore, the GC-ECD method showed that no clean-up steps of acrylamide derivative would be performed prior to injection and was slightly more sensitive than the MS/MS-based methods. Validation and quantification results demonstrated that this method should be regarded as a new, low-cost, and robust alternative for conventional investigation of acrylamide.     

Soxhlet extraction of acrylamide from potato chips

The problem of complete extraction of acrylamide from potato chips was investigated. A method was developed based on the Soxhlet extraction technique. A defatted sample was extracted continuously with methanol, for 10 days, in a Soxhlet extractor. After about 7 days, a constant concentration of acrylamide was reached. This indicates that all the acrylamide that could be removed from the sample had been extracted. Acrylamide was identified in the extract using GC-MS and scan mode. Total concentration was 14500 microg kg(-1) using GC-FID and standard additions. Complementary determinations, using an external standard (GC-FID and GC-MS) and an internal standard (GC-FID), showed results within +/- 5%. A previously published study, using a static extraction method and GC-MS and LC-MS-MS, showed concentrations of 2287 and 1993 microg kg(-1), respectively. The results are discussed in relation to a recent model and analogous experiments. The extracted amount of acrylamide is affected by several parameters: solvent properties, solvent volume, extraction time, temperature, particle size, and the microstructure of the sample.     

Development and single-laboratory validation of a reversed-phase liquid chromatography-electrospray-tandem mass spectrometry method for identification and determination of acrylamide in foods

A rapid and accurate method using reversed-phase liquid chromatography-tandem mass spectrometry interfaced with electrospray was developed for determination of acrylamide in cooked food samples. A simplified sample treatment procedure using an extraction step with acidified water without cleanup was developed. A C18 column with an aqueous formic acid-methanol mixture as the mobile phase was used under isocratic conditions. The method was validated in-house for robustness, limits of detection (LOD) and quantitation (LOQ), linearity, recovery, and accuracy both on standard and baked-product and potato flour matrixes. Good results in the low ppb level were obtained for LOD (< 15 microg/kg) and LOQ (< 25 microg/kg) of acrylamide in samples. Excellent linearity (r2 = 0.999-1.000) was established over 2 orders of magnitude by performing statistical tests. The absence of both constant and proportional systematic errors demonstrated good method accuracy. Excellent results were obtained for intraday repeatability (RSD < 1.5%) and between-day precision (RSD < 5%). Extraction recoveries from food products were calculated in the 97 +/- 3-99 +/- 2% (n = 6) range with a labeled internal standard (13C3-acrylamide). The applicability of the method to determination of acrylamide in cooked food products was demonstrated.     

Collaborative trial validation study of two methods, one based on high performance liquid chromatography-tandem mass spectrometry and on gas chromatography-mass spectrometry for the determination of acrylamide in bakery and potato products

A European inter-laboratory study was conducted to validate two analytical procedures for the determination of acrylamide in bakery ware (crispbreads, biscuits) and potato products (chips), within a concentration range from about 20 microg/kg to about 9000 microgg/kg. The methods are based on gas chromatography-mass spectrometry (GC-MS) of the derivatised analyte and on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) of native acrylamide. Isotope dilution with isotopically labelled acrylamide was an integral part of both methods. The study was evaluated according to internationally accepted guidelines. The performance of the HPLC-MS/MS method was found to be superior to that of the GC-MS method and to be fit-for-the-purpose.     

固相萃取-气相色谱串固相萃取-气相色谱-串联质谱法测定水果中11种三唑类杀菌剂

建立了固相萃取-气相色谱-串联质谱同时测定水果中11种三唑类杀菌剂残留的方法。采用乙腈匀浆提取样品中的待测组分,经固相萃取法(SPE)净化,采用气相色谱-串联质谱在多反应监测(MRM)模式下进行测定,外标法定量。分别对水果样品进行4个水平(10、50、100、250 μg/kg)的加标回收试验,回收率为82.6%～117.1%,相对标准偏差小于10%,定量限(LOQ,以信噪比(S/N)为10计)为0.8～3.4 μg/kg。结果显示该方法的背景干扰低,灵敏度高,定量限低于国家标准及有关文献报道值,适合橘子等水果中三唑类杀菌剂的同时测定。     

Microemulsion electrokinetic chromatography for the analysis of acrylamide in food

The influence of microemulsion electrokinetic chromatography (MEEKC) operating conditions, such as the type of water-immiscible alcohol, aqueous phosphate buffer concentration, pH, as well as the addition of methanol and 2-propanol, on acrylamide migration has been studied. These parameters have been optimized taking into account the presence of matrix signals, in order to avoid the interference of these peaks in acrylamide determination. The best separations were achieved using a microemulsion consisting of 0.8% m/v n-amyl alcohol, 3.3% m/v sodium dodecyl sulfate (SDS), 6.6% m/v 1-butanol, and 89.3% m/v 40 mM phosphate buffer at pH 6.5 working at 15 kV in uncoated silica capillaries. Linear calibration curves over the range studied (1.25-125 microg x mL(-1)), the detection limit (0.70 microg x mL(-1)), and both run-to-run (up to 3.4% for concentration and 1.6% for time values) and day-to-day precision (lower than 11.6% for concentration) have been established. Finally, the applicability of the MEEKC method developed has been demonstrated by analyzing levels of acrylamide present in samples of home-made French fries.     

Evaluation of gas chromatography-tandem quadrupole mass spectrometry for the determination of organochlorine pesticides in fats and oils

A gas chromatography-tandem quadrupole mass spectrometry multi-residue method for the analysis of 19 organochlorine pesticides in fats and oils has been developed. Gel permeation chromatography was employed to remove lipid material prior to GC-MS/MS analysis. Average recoveries of the pesticides spiked at 10 and 50 microg kg(-1) into fish oil, pork fat, olive oil and hydrogenated vegetable oil were typically in the range 70-110% with relative standard deviations generally less than 10%. Calculated limits of detection are between 0.1 and 2.0 microg kg(-1) and results obtained for the analysis of proficiency test materials are in good agreement with assigned values. The higher selectivity of the GC-MS/MS compared to electron capture detection and GC-MS in selective ion monitoring mode allowed unambiguous identification and confirmation of all the target pesticides at low microg kg(-1) levels in fats and oils in a single analysis.