Molecularly imprinted solid-phase extraction for cholesterol determination in cheese products

A new sorbent for molecularly imprinted solid-phase extraction (MISPE) to detect cholesterol (CHO) in food matrices able to work in an aqueous media was synthesized.     

Selective solid-phase extraction using molecular imprinted polymer for the analysis of diethylstilbestrol

A simple imprinted amino-functionalized silica gel material was synthesized by combining a surface molecular imprinting technique with a sol–gel process for solid-phase extraction–high performance liquid chromatography (SPE–HPLC) determination of diethylstilbestrol (DES). Activated silica gel was used as the supporter and non-imprinted silica sorbent was synthesized without the addition of DES using the same procedure as that of DES-imprinted silica sorbent. Compared with non-imprinted polymer particles, the prepared DES-imprinted silica sorbent showed high adsorption capacity, significant selectivity, good site accessibility and fast binding kinetics for DES. The maximum static adsorption capacity of the DES-imprinted and non-imprinted silica sorbent for DES was 62.58 mg g⁻¹ and 19.89 mg g⁻¹, respectively. The relatively selective factor value of this DES-imprinted silica sorbent was 61.7 at the level of 50 mg L⁻¹. And the uptake kinetics was fairly rapid so that the adsorbent equilibrium was achieved within 10 min. Furthermore, the DES-imprinted polymers were used as the sorbent in solid-phase extraction to determine DES in fish samples. The MIP–SPE–HPLC method showed higher selectivity and good recoveries higher than 87.5% (R.S.D. 11.6%).     

Detection of the adulteration of olive oils by solid phase microextraction and multidimensional gas chromatography

The presence or absence of filbertone in 21 admixtures of olive oil with virgin and refined hazelnut oils obtained using various processing techniques from different varieties and geographical origins was evaluated by solid phase microextraction and multidimensional gas chromatography (SPME–MDGC). The obtained results showed that the sensitivity achievable with the proposed procedure was enough to detect filbertone and, hence, to establish the adulteration of olive oil of different varieties with virgin hazelnut oils in percentages of up to 7%. The very low concentrations in which filbertone occurs in some refined hazelnut oils made difficult its detection in specific admixtures. In any case, the minimum adulteration level to be detected depends on the oil varieties present in the adulterated samples. In the present study, the presence of R- and S-enantiomers of filbertone could be occasionally detected in olive oils adulterated with 10–20% of refined hazelnut oil.     

复合添加剂对鲟鱼籽酱(Huso dauricused × sturger schrenckii)挥发性成分的影响

采用固相微萃取-气相色谱-质谱联用分析技术,分别检测未经添加剂处理的鲟鱼籽酱、添加0.5‰山梨酸钾和0.2‰抗坏血酸的鲟鱼籽酱(A1组),添加0.5‰山梨酸钾、0.2‰抗坏血酸和0.2‰乳酸链球菌素(Nisin)的鲟鱼籽酱(A2组),添加0.5‰山梨酸钾、0.2‰抗坏血酸和0.2‰L-抗坏血酸棕榈酸酯的鲟鱼籽酱(A3组),在0℃冷藏时挥发性物质的变化,经NIST 05a.L和NIST 05.l谱库数据库检索,确定其挥发性成分。结果表明:初始鲟鱼籽酱检测出46种挥发性成分,醛类物质作为主要气味贡献组分,其中壬醛、己醛、辛醛和庚醛含量较高,另外,一定含量的D-柠檬烯、长叶烯和石竹烯可能赋予新鲜鲟鱼籽酱独特的柠檬香、木香等清新气味。3组复合添加剂的使用,都有利于防止在贮藏过程中鱼籽酱挥发性物质的流失,减少了酮类和醇类物质的变化。其中,A2组中,山梨酸钾、抗坏血酸和Nisin的添加促进了贮藏3个月后鱼籽酱中醛类物质的还原反应,导致醛类物质的大量减少,酯类物质的大量增加。最后,在贮藏期间醛类物质的变化,显示A1组和A3组复合防腐剂的处理促使鲟鱼籽酱具有更浓的腥味、青草味。     

镍电极对葡萄酒中乙醇测定的研究

葡萄酒经过固相萃取分离出有机酸根等干扰物质后,以镍电极脉冲安培法,结合流动注射技术,测定乙醇含量。方法的回收率为101.2% ～103.4% ,线性动态范围为10- 5～10- 3M,检测限(S/N= 3)为1×10- 6M。     

固相烧结法制备高纯LaCoO3粉末

LaCoO3是典型的ABO3型钙钛矿化合物。它具有优异的化学稳定性和高温下的良导电性，在环境催化分解、汽车尾气处理、巨磁阻材料、二次电池和燃料电池的电极材料等方面都有着十分广泛的应用前景。通过XRD谱和XPS研究发现，固相烧结法制备LaCoO3的最佳配比为Co La=105%，最佳烧结时间为50小时。     

Solid-phase microextraction-liquid chromatography-mass spectrometry applied to the analysis of insecticides in honey

An approach based on solid-phase microextraction-liquid chromatography-mass spectrometry (SPME-LC-MS) has been developed for determining 12 insecticides (bromophos ethyl, chlorpyrifos methyl, chlorpyrifos ethyl, diazinon, fenoxycarb, fonofos, phenthoate, phosalone, pirimiphos methyl, profenofos, pyrazophos, and temephos) in honey. The influence of several parameters on the efficiency of the SPME was systematically investigated. Under optimal conditions, the procedure provided excellent linearity (>0.990), detection and quantification limits (between 0.001 and 0.1?µg?g^?1 and between 0.005 and 0.5?µg?g^?1, respectively), and precision (<19% at the quantification limits and from 6 to 14% at ten times higher concentrations). However, recoveries were not so good, ranging from 19 to 92%. Honey samples were found that were contaminated with bromophos ethyl, diazinon, fonofos, pirimiphos ethyl, pyrazophos, and temephos at estimated concentrations from 6.2?±?1.2 to 19?±?3?ng?g^?1.     

人促甲状腺激素生物素—亲和素系统免疫放射分析法的建立

报道将ＢＡＳ引入双们点夹心ＩＲＭＡ，建立了人血清ＴＳＨ固相试管双位点夹心ＢＡＳ－ＩＲＭＡ。该法批内ＣＶ为１．４％－８．３％，批间ＣＶＯ ６．１％－８．４％，最小检出量为０．０４ｍＩＵ／Ｌ，平均回收率为１００．１６％，灵敏度约是同条件下ＩＲＭＡ的３倍；与ＩＲＭＡ对比测定２０份病人血管ＴＳＨ样品，经统计学处理，两者测定结果呈良好相关性。     

不同部位宁乡花猪肉风干香肠挥发性风味成分的鉴定与分析

为了解宁乡花猪独特肉质特性在其风干香肠制品香气形成中的作用,以取自四个不同部位的宁乡花猪肉制成的风干香肠为研究对象,采用固相微萃取/气相色谱-质谱联用技术（solid-phase micro-extraction/gas chromatographymass spectrometry,SPME/GC-MS）对其挥发性风味成分进行提取、鉴定及分析。共鉴定出35种挥发性风味成分,其中醇类2种、醛类18种、酯类6种、烃类7种及其他类化合物2种。醛类、酯类及烃类在各样品中的种类及含量最丰富,是宁乡花猪肉风干香肠的特征风味成分。分析表明,醛类及酯类对产品的香气贡献最大,且其丰富度与宁乡花猪肉高油酸、亚油酸等不饱和脂肪酸的特性密切相关。不过,这种作用在不同部位猪肉制成的风干香肠制品间存在明显的差异。