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%。     

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。     

气相色谱-质谱法测定油炸淀粉类食品中的丙烯酰胺

 建立了油炸淀粉类食品中丙烯酰胺的溴衍生化气相色谱-质谱(GC-MS)测定方法。样品经水提取、高速离心、石墨化 炭黑柱净化、溴衍生化后,以GC-MS选择离子进行定性,同位素稀释技术定量。该方法的检出限为5 μg/kg,回收率为90％ ～105％,相对标准偏差为6.3％。利用该方法对市场上某些油炸淀粉类食品进行了初步测定,发现薯片和炸薯条中含有27 8~4518 μg/kg的丙烯酰胺。     

A sensitive confirmatory method for aflatoxins in maize based on liquid chromatography/electrospray ionization tandem mass spectrometry

A liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method for measurement of aflatoxins B1, B2, G1, and G2 in maize is described. Aflatoxins (AFs) were extracted from 1 g samples by using tri-portions of acetonitrile/water (80:20, v/v) (10 + 7 + 7 mL), and 2/5 of the extract diluted to 500 mL by water was cleaned up with a 100 mg Carbograph-4 cartridge. After the addition of the internal standard AFM1, the final extract was analyzed by LC/ESI-MS/MS in positive ion mode using multiple reaction monitoring with a triple-quadrupole instrument. A C(18) column thermostatted at 45 degrees C with a mobile phase gradient of acetonitrile/water with 2 mmol/L ammonium formate was used. Although the matrix suppression effect was negligible, quantitation was achieved by an external calibration procedure using matrix-matched standard solutions to improve accuracy. Sample recoveries at four spiking levels ranged from 81 to 101% (relative standard deviation (RSD) 相似文献   

液相色谱-串联质谱法测定肉及肉制品中利谷隆及其代谢产物3,4-二氯苯胺残留

建立了液相色谱-串联质谱分析多种肉及肉制品中利谷隆及其代谢产物3,4-二氯苯胺残留的方法。样品用丙酮-乙腈(5:95, v/v)提取,冷冻去脂,经弗罗里硅土固相萃取柱净化后进行液相色谱-串联质谱检测,采用内标法定量。利谷隆及3,4-二氯苯胺在1～500 μg/L范围内呈良好的线性关系,相关系数(r)均大于0.998,方法的定量限(信噪比(S/N)＞10)为10 μg/kg,检出限(S/N＞3)为5 μg/kg。在各种肉及肉制品基质中添加低、中、高3种不同水平的利谷隆及3,4-二氯苯胺,其回收率范围分别为88.3%～101.2%和91.6%～101.6%,相对标准偏差(RSD)分别为4.8%～13.7%和4.7%～11.8%。结果表明所建立的方法可以满足肉及肉制品中利谷隆和3,4-二氯苯胺残留量的检测需要。     

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.     

Development of a quantitative method for determination of acrylamide in infant powdered milk and baby foods in jars using isotope dilution liquid chromatography/electrospray ionization tandem mass spectrometry

An improved method has been developed for the determination of acrylamide in infant powdered milk and baby foods in jars, a particular class of foodstuffs which represent an important source of nutrition for young infants and babies. This method uses isotope dilution liquid chromatography coupled to a tandem mass spectrometer with electrospray ionization and is significantly more sensitive than previous published methods with a limit of quantification estimated at 1 microg kg(-1). The new method offers effective sample preparation procedures including defatting with petroleum ether, extraction with aqueous solution of sodium chloride, further liquid-liquid extraction with ethyl acetate and clean-up by solid-phase extraction (SPE) with HLB 200 mg cartridges. The analytical method was well validated and good results were obtained with respect to repeatability (RSD < 5%) and recovery (86-97%) which fulfilled the requirements defined by European Union (EU) legislation. The acrylamide level in infant powdered milk and baby foods in jars were 3.01-9.06 microg kg(-1) and 6.80-124.93 microg kg(-1), respectively. Especially, this new method is successfully applied to the trace quantification of acrylamide in infant/baby foods, the content of which is less than 10 microg kg(-1).     

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。     

超高效液相色谱-大气压化学电离-串联质谱法测定烘焙咖啡中丙烯酰胺

建立了烘焙咖啡中丙烯酰胺的超高效液相色谱-大气压化学电离-串联质谱（UHPLC-APCI-MS/MS）分析方法。样品经甲醇提取，HLB固相萃取（SPE）小柱净化，Brownlee validated AQ C18色谱柱分离，采用大气压化学电离（APCI）源，正离子扫描和多反应监测（MRM）模式对丙烯酰胺进行检测，内标法定量。结果表明，丙烯酰胺在0.5~100.0 μg/L范围内具有良好的线性关系，相关系数（r²）为0.999，方法检出限为5.0 μg/kg，定量限为10.0 μg/kg。在100.0、200.0和1000.0 μg/kg添加水平下，丙烯酰胺的回收率为94.6%~115.0%，相对标准偏差（RSD）值为2.8%~3.6%（n=6）。本方法采用APCI源作为离子化方式，能有效地减少咖啡基质对丙烯酰胺的基质干扰，前处理简单，灵敏度高，适用于咖啡中丙烯酰胺的日常检测。     

气相色谱-质谱法同时测定动物内脏中的14种酞酸酯类环境激素残留

开展了动物内脏中14种酞酸酯类（PAEs）环境激素残留的气相色谱-电子轰击离子源/质谱（GC-EI/MS）的分析方法研究。优化与选择了动物内脏样品的前处理条件,动物内脏样品经正己烷/二氯甲烷（1/1,v/v）混合提取剂超声提取、Florisil硅藻土固相萃取柱净化与乙酸乙酯/正己烷（2/3,v/v）混合洗脱剂洗脱和浓缩后,以邻苯二甲酸二苯基酯（DPhP）为内标物,采用GC-EI/MS的选择离子监测方式（SIM）进行定性和定量分析。当猪肝样品的加标浓度水平为100、200、400 μg/kg时,加标回收率为：60%~110%,相对标准偏差为：0.78%~10.3%;除邻苯二甲酸二（2-甲氧基乙基）酯（DMEP）与邻苯二甲酸二（2-乙氧基乙基）酯（DEEP）的检测限（MDL）分别为3.30与2.25 μg/kg外,其余的12种PAEs的MDL ≦ 1.74 μg/kg;线性范围为50 ~ 800 μg/kg,相关系数都大于0.9994。此分析方法成功地应用于6种动物内脏中14种痕量PAEs残留的分析。     

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.     

Determination of isopropyl-9H-thioxanthen-9-one in packaged beverages by solid-phase extraction clean-up and liquid chromatography with tandem mass spectrometry detection

A simple method was developed and validated for the trace determination of 2-isopropylthioxanthone (ITX) in packaged drinks. Samples were extracted from the food matrix using acetonitrile:water (60:40, v/v), and further subjected to clean-up and preconcentration using solid-phase extraction prior to analysis by liquid chromatography-tandem mass spectrometry using multiple reaction monitoring (MRM) mode. The use of 2-isopropyl-[(2)H7]thioxanthen-9-one was incorporated into the method as an internal standard. Excellent 3-day interday precision data (RSD 0.72%, n=10), and intraday precision data (RSD 0.52%, n=10) were obtained on a 0.10 microg/L standard solution. Spiked samples (n=8) were used to gauge the accuracy of the method at the concentration levels of 2.5, 100, and 500 microg/kg in food; recoveries ranged from 97.0 to 103.0%. These excellent validation data suggest the exciting possibility of using this method for the determination of low levels of ITX migrating from printed food packaging materials into beverages with a method quantitation limit of 0.50 microg/kg. For the first time, analysis on a range of milk, juice, tea and yoghurt drinks, as well as their respective food packaging materials were performed for comparative studies on their ITX content.     

气相色谱-质谱法分析蜂蜜中的多种农药残留

开展了蜂蜜中23种农药残留的气相色谱-电子轰击离子源质谱(GC-EI/MS)分析方法的研究,并对其中3种农药的EI/MS碎片离子的断裂机理与结构进行了初步解析。探讨了蜂蜜试样前处理条件的优化与选择。将蜂蜜试样用乙酸乙酯提取剂超声提取、Florisil硅藻土色谱柱净化和正己烷-乙酸乙酯(体积比为7∶3)混合洗脱剂洗脱后,以PCB103为内标物,采用选择离子监测(SIM)方式下的GC-EI/MS分析。当试样的加标浓度为50,100和200 μg/kg时,加标回收率为82%～120%,相对标准偏差小于11.0%。23种农药的检测限都小于10.0 μg/kg,线性范围为10～500 μg/kg,相关系数都大于0.995。此分析方法已成功地应用于蜂蜜中23种痕量农药残留的分析。     

Determination of iguratimod in rat plasma by high performance liquid chromatography: method and application

A high-performance liquid chromatographic method with UV detection has been developed for the determination of iguratimod (T-614) in rat plasma. Plasma was precipitated with acetonitrile after the addition of the internal standard (IS), N-[4-(2-formylaminoacetyl)-5-methoxy-2-phenoxyphenyl]-methanesulfonamide. The chromatographic separation was achieved on a reversed-phase C(18) column with the mobile phase acetonitrile-acetic acid aqueous solution, pH 4.5 (40:60, v/v), at a flow rate of 1 mL/min, and the UV detection wavelength was set at 257 nm. The calibration curve was linear over the range 0.10-50.0 microg/mL, and the lower limit of quantification was 0.10 microg/mL. The intra- and inter-day relative standard deviations were all less than 11.5%. The method has been successfully applied to study the pharmacokinetics of iguratimod in rats. A single 10 mg/kg dose of iguratimod was given to the rats by intragastric administration. The mean maximum plasma concentration of iguratimod for the six rats was 14.5 microg/mL, and the mean elimination half-life of iguratimod was 4.0 h.     

一种新型固相萃取柱结合超高效液相色谱-串联质谱法选择性富集测定猪肉中的盐酸克伦特罗

发展了一种测定猪肉中盐酸克伦特罗残留的简便、高效、准确的固相萃取-超高效液相色谱-串联质谱(SPE-UPLC-MS/MS)的方法。将搅碎的猪肉样品用5%(v/v)高氯酸超声提取,再以10000 r/min离心15 min后,上清液用SMCX固相萃取柱进行富集和净化。因SMCX是以硅胶为基质兼有反相/强阳离子交换的混合作用模式,因此可以有效地去除复杂基质干扰,达到目标样品的选择性富集和净化的目的。方法学结果表明,该方法在0.25～50 μg/kg范围内具有良好的线性关系,相关系数r为0.9982; 3个添加水平(1.25、12.5、50 μg/kg)的平均回收率为62.2%～ 72.0%,相对标准偏差(RSDs)为4.2%～ 6.1%;检出限(S/N=3)为0.05 μg/kg。所发展的样品前处理和检测方法简单、快速,可用于瘦肉精类成分的选择性富集和分离检测。     

Analysis of T-2 and HT-2 toxins in cereal grains by immunoaffinity clean-up and liquid chromatography with fluorescence detection

A sensitive, precise and accurate method has been developed for the simultaneous determination of T-2 and HT-2 toxins in cereal grains at ppb levels using high-performance liquid chromatography (HPLC) with fluorescence detection and 1-antroylnitrile (1-AN) as labeling reagent after immunoaffinity clean-up. Cereal samples were extracted with methanol/water (90:10, v/v), and the extracts were cleaned-up through commercially available immunoaffinity columns containing monoclonal anti-T-2 antibodies (T-2 test HPLC, Vicam). T-2 and HT-2 toxins were quantified by reversed-phase HPLC with fluorometric detection (excitation wavelength 381 nm, emission wavelength 470 nm) after derivatization with 1-AN. The monoclonal antibody showed 100% cross-reactivity with both T-2 and HT-2 toxin, and the immunoaffinity column clean-up was effective up to 1.4 microg of both toxins. The method was successfully applied to the analysis of T-2 and HT-2 toxins in wheat, maize and barley. Recoveries from spiked samples with toxin levels from 25 to 500 microg/kg ranged from 70% to 100%, with relative standard deviation generally lower than 8%. The limit of detection of the method was 5 microg/kg for T-2 toxin and 3 microg/kg for HT-2 toxin, based on a signal-to-noise ratio 3:1. HT-2 toxin was detected in ten naturally contaminated wheat samples out of 14 samples analyzed, with toxin levels ranging from 10 to 71 microg/kg; three of them contained also T-2 toxin up to 12 microg/kg.     

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.     

Studies on the stability of acrylamide in food during storage

Acrylamide levels in a variety of food samples were analyzed before and after 3 months of storage at 10 degrees-12 degrees C. The analysis was performed by liquid chromatography tandem mass spectrometry (LC/MS/MS) using deuterium-labeled acrylamide as internal standard. Acrylamide was stable in most matrixes (cookies, cornflakes, crispbread, raw sugar, potato crisps, peanuts) over time. However, slight decreases were determined for dietary biscuits (83-89%) and for licorice confection (82%). For coffee and cacao powder, a significant decrease occurred during storage for 3 or 6 months, respectively. Acrylamide concentrations dropped from 305 to 210 microg/kg in coffee and from 265 to 180 microg/kg in cacao powder. On the contrary, acrylamide remained stable in soluble coffee as well as in coffee substitutes. Reactions of acrylamide with SH group-containing substances were assumed as the cause for acrylamide degradation in coffee and cacao. Spiking experiments with acrylamide revealed that acrylamide concentrations remained stable in baby food, cola, and beer; however, recovery levels dropped in milk powder (71%), sulfurized apricot (53%), and cacao powder (17%). These observations suggest that variations in the acrylamide content of food, especially in coffee and cacao, can vary depending on the storage time because special food constituents and/or reaction products can affect the levels.     

高效液相色谱法测定大鼠血浆中的原儿茶酸

建立了大鼠血浆中原儿茶酸含量测定的高效液相色谱方法。采用的色谱柱为DiamondsilTM C18 柱(150 mm×4.6 mm,5 μm);流动相为乙腈-水(体积比为9∶91,用H3PO4 调pH至2.5);流速1.2 mL/min;检测波长260 nm;内标为对羟基苯甲酸。原儿茶酸的线性范围为0.050~3.20 mg/L,线性相关系数为0.9978，最低定量限为0.050 mg/L,日内和日间测定的精密度（以相对标准偏差表示）均低于7.0%,准确度（以相对误差表示）为-1.4%～2.6%；在0.050,0.40,3.20 mg/L低、中、高3个添加浓度水平下，血浆样品的提取回收率分别为83.4%,87.3%,91.1%。该方法简便,灵敏,准确,适用于大鼠体内原儿茶酸的药物动力学研究。     

高效液相色谱-质谱法测定比格犬血浆中的艾普拉唑及其药代动力学

运用高效液相色谱-电喷雾质谱(HPLC-ESI-MS)技术,建立了快速、简单、灵敏的比格犬静脉滴注艾普拉唑钠盐后血药浓度的检测方法。血浆样品采用蛋白沉淀法,以丁螺环酮作为内标,色谱柱为Teknokroma Kromasil C18(100 mm×2.1 mm, 5 μm),流动相为水-甲醇-乙腈(69:8:23, v/v/v)(含0.1%的甲酸),流速0.2 mL/min,采用电喷雾(ESI)离子源以正离子方式检测。绘制血药浓度-时间曲线,并采用DAS 2.0计算药代动力学参数。方法学实验结果表明内源性杂质不干扰艾普拉唑和内标的测定,线性范围为5～10000 μg/L (r=0.994),最低定量限为5 μg/L,精密度和准确度均符合生物样品测定的要求。低、中、高3个浓度的绝对回收率在106%左右,基质效应小于142.0%,表明该方法适合比格犬血浆中艾普拉唑浓度的测定及药代动力学研究。比格犬静脉滴注艾普拉唑钠盐3个剂量(0.2 mg/kg、0.8 mg/kg和3.2 mg/kg)后的药-时曲线下面积(AUC(0~∞))分别为(2.4×104±3×103)、(8.8×104±1.6×104)和(5.4×105±8×104) μg/L•min,呈线性药物代谢动力学过程。