食品安全分析样品前处理-快速检测联用方法研究进展

综述了近年来传感器、可视化分析、便携光谱、酶联免疫检测及便携气相色谱等食品安全快速检测技术的研究现状,以及食品安全分析中样品前处理-快速检测联用技术的研究进展,为发展选择性好、准确度高、可定量的新型食品安全快速检测技术提供参考。     

液相色谱紫外法测定鸡肉中三种硝基咪唑残留量

建立了测定鸡肉中二甲硝咪唑、罗硝唑、甲硝唑残留量的方法。以二氯甲烷提取,硅胶固相萃取净化,液相色谱紫外法检测。样品添加１０μｇ／ｋｇ,５０μｇ／ｋｇ,平均回收率为７８％～９１％,相对标准偏差为６．４％～１０．１％。     

多壁碳纳米管固相萃取-高效液相色谱-串联质谱法测定食品接触材料中双酚-二环氧甘油醚的迁移量

建立了测定食品接触材料中6种双酚-二环氧甘油醚(双酚A二缩水甘油醚(BADGE)及其衍生物双酚A(2,3-二羟丙基)甘油醚(BADGE•H2O)、双酚A(3-氯-2-羟丙基)甘油醚(BADGE•HCl)、双酚A(3-氯-2-羟丙基)(2,3-二羟丙基)醚(BADGE•H2O•HCl)和双酚F二缩水甘油醚(BFDGE)及其衍生物双酚F双(3-氯-2-羟丙基)甘油醚(BFDGE•2HCl))迁移到食品中的迁移量的高效液相色谱-串联质谱法(HPLC-MS/MS)。样品以叔丁基甲醚(MTBE)为提取溶剂,超声提取,提取液经多壁碳纳米管(MWCNTs)固相萃取(SPE)柱富集、净化。以COSMOSIL C18为分析柱,流动相为0.1%甲酸的5 mmol/L醋酸铵溶液和甲醇。6种双酚-二环氧甘油醚在1.0～100 μg/L范围内线性关系良好(r2＞0.9991)。在3个添加水平下,6种目标化合物的回收率范围为78.6%～89.9%,相对标准偏差小于10%。方法检出限范围为0.5～1.5 μg/L。该方法操作简单,灵敏度高,可应用于食品接触材料中双酚-二环氧甘油醚迁移量的快速检测。     

高效液相色谱-电喷雾电离三级四极杆质谱检测动物源食品中氯霉素、甲砜霉素、氟苯尼考残留量

建立了动物源产品中氯霉素、甲砜霉素、氟苯尼考残留量的高效液相色谱-电喷雾电离三级四极杆质谱(LC-ESI-MS/MS)的方法。前处理方法包括添加同位素内标氯霉素-d5,碱化乙酸乙酯提取,C18小柱净化。该方法采用负离子,多反应监测氯霉素四对离子(321.0/151.9,321.0/256.6,321.0/194.2,321.0/175.4),甲砜霉素两对离子(354.1/185.0,354.1/290.0),氟苯尼考两对离子(356.0/335.9,356.0/185.1)和同位素内标氯霉素-d5(326.0/157.1)。该方法线性范围为0.1~1.6μg/kg;对不同基质样品的加标回收率为80%~112.5%;相对标准偏差小于11%;方法的测定低限为0.1μg/kg。     

固相微萃取技术的进展及其在食品分析中应用的现状

固相微萃取(SPME)是当今色谱分析中使用极为广泛的样品前处理方法,这一技术将萃取、浓缩、解吸、进样等功能集于一体,灵敏度高且操作简便。该文简要介绍了近年来SPME涂层、装置及相应技术的演变,综述了SPME在国内外食品分析中的应用现状,并讨论了国内部分研究者在采用这一技术进行定量分析时存在的一些共性问题。     

γ-Radiation Effects on the Thermal Stability of Bovine γ-Globulin

Low-dose γ-radiation produces subtle effects on bovine γ-globulin, as revealed by calorimetric investigations carried out on concentrated aqueous solutions. The irradiation rate used seems below the threshold that allows complete protein denaturation; the denaturation temperature, T_d, remained unaffected; nonetheless, modifications of the shape of the calorimetric signal reveal that other changes, such as the dissociation of protein oligomers, could take place. This revised version was published online in July 2006 with corrections to the Cover Date.     

Periodic Solution of a Nonautonomous Diffusive Food Chain System of Three Species with Time Delays

Abstract By using the continuation theorem of coincidence degree theory,the existence of a positive periodicsolution for a nonautonomous diffusive food chain system of three species. dx_1(t)/dt=x_1(t)[r_1(t)-a_(11)(t)x_1(t)-a_(12)(t)x_2(t)]+D_1(t)[y(t)-x_1(t)], dx_2(t)/dt=x_2(t)[-r_2(t)+a_(21)(t)x_1(t-r_1)-a_(22)(t)x_2(t)-a_(23)(t)x_3(t)], dx_3(t)/dt=x_3(t)[-r_3(t)+a_(32)(t)x_2(t-r_2)-a_(33)(t)x_3(t)], dy(t)/dt=y(t)[r_4(t)-a_(44)(t)y(t)]+D_2(t)[x_1(t)-y(t)]+D_2(t)[x_1(t)-y(t)],is established,where,r_i(t),a_(ii)(t)(i=1,2,3,4),D_i(t)(i=1,2),a_(12)(t),a_(21)(t),a_(23)(t)and a_(32)(t) are all positiveperiodic continuous functions with period w>0,T_i(i=1,2)are positive constants.     

Optimal harvesting for an age-dependent <Emphasis Type="Italic">n</Emphasis>-dimensional food chain model

This paper is concerned with optimal harvesting policy for an age-dependent n-dimensional food chain model. The existence and uniqueness of non-negative solution of the system are proved using the fixed point theorem. By Mazur＇s theorem, the existence of optimal control strategy is demonstrated and optimality conditions derived by means of normal cone.     

Determination of Synthetic Phenolic Antioxidants in Vegetable Oil and Oil-Enriched Foods by High-Performance Liquid Chromatography with Electrochemical Detection

Three synthetic phenolic antioxidants, tertiary butyl hydroquinone, butylated hydroxytoluene, and butylated hydroxyanisole, were determined in vegetable oil and oil-enriched food by high-performance liquid chromatography (HPLC) with electrochemical detection. The separation was achieved using a reverse-phase column and gradient elution with methanol and 1% acetic acid. The limits of detection and quantification of the analytes were 2–120 lower, higher than those obtained by diode-array detection. The recoveries were 103.3% for tertiary butyl hydroquinone, 97.3% for butylated hydroxyanisole, and 95.2% for butylated hydroxytoluene. The results showed that HPLC with electrochemical detection is suitable for the quantification of low concentrations of phenolic antioxidants in vegetable oil and oil-enriched food with high sensitivity and accuracy.     

Migration of Stabilizers from Polypropylene into Simulated Food

This study has investigated the migration of stabilizers from three polypropylene materials: a polypropylene homopolymer, a polypropylene block copolymer, and a polypropylene random copolymer in 10% ethanol, 3% acetic acid, 20% ethanol, 50% ethanol, and isooctane according to Regulation (EU) No. 10/2011. Measurements were performed at 20, 40, and 70°C and migration was evaluated from 10?min to 10 days. Measurements were performed by high-performance liquid chromatography (HPLC) with external calibration. The HPLC method provided high correlation coefficients, good precision, good accuracy, and suitable reproducibility. Diffusion coefficients for stabilizers were obtained using a rigorous model based on Fick’s second law and the values were between 6.1?×?10^?13 and 3.8?×?10^?9?cm²?s^?1. By applying an Arrhenius-type equation to the diffusion coefficients, an estimation of activation energy of the diffusion was obtained. The activation energies were from 39.97 to 98.75?kJ?mol^?1 for the stabilizers. The results indicate that the polypropylene material structure influenced the migration rate, which decreased in the order of the increasing crystallinity in the materials. The diffusion coefficients for stabilizers in the polypropylene random copolymer were higher than in the polypropylene block copolymer and polypropylene homopolymer. The random polypropylene copolymer had the lowest activation energy. These results show that a higher diffusion coefficient indicates a higher migration rate, and a system with a lower activation energy allows more migration.