神经网络-光度法同时测定食品中防腐剂和甜味剂

根据食品中常用防腐剂本甲酸和山梨酸及甜味剂糖精钠在紫外区均有吸收的特点，建立了一种以紫外分光光度法为基础对该三组分同时测定的方法，光谱数据采用作者自编的径向人工神经网络MATLAB程序进行处理，苯甲酸、山梨酸和糖精钠的平均标准偏差分别为1.60%、5.23%和1.21%，回收率大为95.0-102.0%之间，将该法应用于食品中二组分的测定，获得较为满意的结果。     

Verifying the red wines adulteration through isotopic and chromatographic investigations coupled with multivariate statistic interpretation of the data

The assessment of wine traceability and authenticity is a major concern that has gained a lot of interest internationally since the wine has always been subjected to various fraudulent practices. Practiced since ancient times, wine fraud has become more sophisticated in the present day, taking many forms. Consumers, regulatory bodies and manufacturers are all interested to have reliable analytical tools and information to allow the authentication and detection of wine adulteration or incorrect labelling. This research study evaluates and proposes a possible strategy for the detection of adulterated sweet or medium sweet red table wines using appropriate chemical parameters which can reveal prohibited practices in the winemaking process. The work is performed on 29 table wine samples, bought from the market, packed in PET bottles. Exogenous addition of sugar and water in the counterfeited table red wines was detected by the measurement of stable isotopes content (δ¹³C and δ¹⁸O) known as origin markers and supplementary confirmed by other classical parameters, as the alcoholic strength of the wines (‰ vol.) and the presence of 5-(hydroxymethyl)-2-furaldehyde (HMF) and of synthetic sweeteners or synthetic red dyes used to correct deficiencies of taste and colour. Additionally, the nature and profile of anthocyanins, as indicator of the red colour of wine, was investigated in the table wines and then compared with that of authentic wines obtained by microvinification of Vitis vinifera, in order to determine their authenticity.     

Direct Determination of Saccharin and Acesulfame-K in Sweeteners and Fruit Juices Powders

A simple and rapid analytical procedure for determination of saccharin (SAC) and acesulfame-K (AC-K) based on UV-vis measurements and partial least squares (PLS) was proposed. Thus, an experimental design at levels 2 and 15 mg l⁻¹ for SAC and 2 and 20 mg l⁻¹ for AC-K was applied. Because real samples usually contain SAC and AC-K combined with aspartame (ASP), this interference was also included in the model. The procedure was successfully applied for SAC and AC-K simultaneous determination in sweeteners and fruit juice powders, without any separation step to remove ASP. The results were validated by using spiked samples, and the obtained recoveries were satisfactory.     

高效液相色谱法测定食品中糖精钠和天冬糖

利用高效液相色谱测定食品和复合甜味剂蛋白糖中人工合成甜味剂-糖精钠和天冬糖,采用国产C     

液相色谱串联质谱法同时测定饮料和糕点中安赛蜜、糖精钠、甜蜜素

文章研究了饮料和糕点样品中安赛蜜、糖精钠和甜蜜素3种人工合成甜味剂的高效液相色谱串联质谱（HPLCMS／MS）同时检测方法。采用ZORBAXSB—C18色谱柱,对流动相的组成以及质谱的各种参数进行了优化。结果表明,在ESI负离子模式下,采用多反应监测模式进行测定时,安赛蜜、糖精钠、甜蜜素的检出限分别为3．60、7．2、0．63μg／kg：三水平六平行添加实验,回收率为88．9％～102．3％,相对标准偏差为2．6％～5．3％。该方法检出限低,简单、快速、准确,可用于实际样品的测定。     

Occurrence of caffeine,saccharin, benzoic acid and sorbic acid in soft drinks and nectars in Portugal and subsequent exposure assessment

A reliable method for the determination of benzoic and sorbic acids, caffeine and saccharin in soft drink and nectars using high performance liquid chromatography and UV detection was validated. The chromatographic separation was achieved with a C18 column (250 × 4.6 mm) and one buffered mobile phase, KH₂PO₄ 0.02 M/ACN (90:10)/phosphoric acid at pH 4.2. The effluent was monitored at 220 nm.     

高效液相色谱法快速测定饮料中的苯甲酸、山梨酸和糖精钠

将饮料样品定量稀释后，用针筒式水膜过滤器处理后，直接进样，外标法进行液相色谱定性、定量分析。用此方法进行了不同水平的加标回收率测试，证明方法快捷可靠，非常适用于大量的样品的快速测定。     

食品中糖精钠的荧光猝灭薄层扫描测定

研究了荧光猝灭薄层扫描祛测定食品中的糖精钠。此法最低检出量为0.6ug,在0.6～18.0ug范围内,糖精钠含量与峰积分值呈良好的线性关系,相关系数为的0．9995。回收率为90.1％～101.9％,变异系数为1．9％～3．3％。用此法检测了广州市售30种食品中糖精纳的含量。     

胶束电动毛细管色谱法同时测定食品饮料中的四种添加剂

采用胶束电动毛细管色谱法,用50μm×27cm熔融石英毛细管柱,以pH8.0的20mmol/L硼砂 5mmol/LSDS作缓冲溶液,工作电压25kV,检测波长214mm,压力进样1s为分离条件,对5种饮料和1种食品中4种食品添加剂(咖啡因、苯甲酸、山梨酸和糖精)进行了测定同时讨论了工作电压、缓冲液浓度与pH、SDS浓度和内标对测定的影响     

Internal stress and adhesion of amorphous Ni–Cu–P alloy on aluminum

This study investigated the effect of saccharin on the internal stress and the adhesion of amorphous Ni–Cu–P deposited on aluminum. An amorphous Ni–Cu–P deposit with slight compressive stress can be produced when one adds 8–10 g/l saccharin into the Ni–Cu–P deposition solution. The stress relief mechanism was investigated. The addition of saccharin restrains the coalescence of the islands within Ni–Cu–P nodules and reverses the internal stress of the electroless Ni–Cu–P deposit from tensile to compressive. The adhesion strength of the Si/Ti/Al/Ni–Cu–P multilayer specimen obtained with 10 g/l saccharin is around 35 to 45 MPa, and the fracture occurs at the silicon substrate after the pull test. The shear strength of the Ti/Al/Ni–Cu–P bump (100×100 μm) on Si is 132.9±12.7 g, and the fracture occurs at the Ni–Cu–P deposit after the shear test. Moreover, the inhibition of coalescence of the fine islands within Ni–Cu–P nodules increases the brightness and the hardness of the deposit.