软饮料中糖的测定

应用高效液相色谱法测定了国外8种软饮料中的果糖、葡萄糖、蔗糖、麦芽糖和异麦芽糖的含量。测定时,将折光检测器与质量检测器串接联用,以折光检测器测定含量高的糖,以质量检测器测定含量低的糖。异麦芽糖的检出可以证实该软饮料以玉米糖浆作甜味剂。     

Determination of Synthetic Colors in Soft Drinks and Confectioneries by Micellar Electrokinetic Capillary Chromatography

A method of micellar electrokinetic capillary chromatography (MEKC) was developed for simultaneous determination of 14 synthetic colors in soft drinks and confectioneries. The optimal solvent of MEKC method for separating all colors was a mixed solution comprised of 18% acetonitrile and 82% 0.05 M sodium deoxycholate in borate‐phosphate buffer (pH 7.8). These colors were well separated within 20 min using 57 cm × 75 micrometer uncoated fused‐silica capillary column, operating at 25 kV and detected by UV at 214 nm. The average recovery of all colors spiked into soft drinks and confectionery was better than 82%. The addition of illegal colors was not found after testing 30 samples. In retail foods, the colorant found in highest concentration was tartrazine (155 μLgg/g sample).     

Development and Validation of a LC-FD Method for the Simultaneous Determination of Eight Bisphenols in Soft Drinks

Bisphenol A (BPA) is a chemical widely used as a monomer in the production of polymers of plastics. It acts as an endocrine-disrupting agent and thus its contaminations of food and beverage should be carefully monitored in order to assess consumers’ risk. In this study, we propose a liquid chromatography-fluorescence detection (LC-FD)-validated method for the simultaneous determination of BPA and seven analogues, i.e., bisphenol AF, bisphenol B, bisphenol E, bisphenol F, BPA diglycidyl ether, bisphenol F diglycidyl ether, and Bisphenol M in soft drinks. A one-step solid-phase extraction (SPE) was effective at reducing the interferences, obtaining good purification of the samples, and consequently good recoveries of all analytes. The separation was obtained on a C18 column by using acetonitrile/water 55:45 (v/v) under isocratic conditions. Method validation was performed according to the European Commission Decision 2002/657/EC criteria, providing good results regarding the analytical parameters of linearity, selectivity, sensitivity, precision, recovery, decision limit (CCα), detection capability (CCβ), limit of detection (LOD), limit of quantification (LOQ), stability, and robustness. The method allows the detection of BPA and BADGE at levels much lower than their legal limits in the food, which are 0.06 and 9.00 mg kg^?1, respectively.     

纳米多孔金电化学传感器构建及其对饮品中抗坏血酸的检测

基于纳米多孔金（nanoporous gold,NPG）对抗坏血酸的强电催化氧化作用,通过酸腐蚀制备NPG,构建纳米多孔电极（NPG/GCE）检测饮料中的抗坏血酸。通过循环伏安法和差分脉冲伏安（differential pulse voltammetry,DPV）法对抗坏血酸检测条件进行优化,确定最佳检测条件为pH 4.0的柠檬酸缓冲液。在优化条件下,利用DPV法对抗坏血酸进行检测,结果表明：在6.652 8～160 μg/mL的范围内,峰电流密度与抗坏血酸质量浓度呈良好的线性关系;该电极制备简单、灵敏度高、稳定性和抗干扰能力强,对饮料中抗坏血酸的快速检测有良好的应用潜力。     

高效液相色谱法同时测定饮料中十种着色剂

建立了饮料中10种人工着色剂(柠檬黄、日落黄、胭脂红、苋菜红、诱惑红、赤藓红、亮蓝、新红、酸性红、罗丹明B)的高效液相色谱测定方法。样品调pH值后,采用Welch Ultimate XB-C18色谱柱(4.6mm×150mm,5μm),以0.02mol/L乙酸铵和甲醇梯度洗脱,采用紫外检测器检测。10种人工合成色素在0.8-40mg/L范围内线性良好,相关系数(r)都在0.999以上,方法加标回收率为90.3-108.0%。该方法简便,易操作,灵敏度高,分离度好,适用于饮料中10种着色剂的同时测定。     

软饮料中人工合成色素快速测定试纸条的研制

基于聚酰胺薄膜与人工合成色素之间的特异性吸附的原理,建立一种快速、低成本的测定软饮料中最常用的3种人工合成色素(胭脂红E124、柠檬黄E102、日落黄E110）的方法。在优化后的检测条件下,3种色素的最低检测限分别为0.4、0.3mg/L和0.4mg/L,检测时间10min。对14个市售样品进行检测,结果表明,建立的快速检测方法与薄层色谱和高效液相色谱两种方法的结果吻合。该方法操作简单、不需要仪器设备,凭肉眼判读,可用于现场检测和快速筛查,为控制和监测合成色素的滥用或过量添加提供技术途径。     

二甲酚橙光度法测定饮料中的微量汞

在非离子表面活性剂阿拉伯树胶(ARG)存在下,饮料中汞(Ⅱ)与二甲酚橙(XO)在水相中发生显色反应形成深红色配合物。结果表明,配合物的最大吸收波长为580 nm,摩尔吸光系数为4.65×10~5 L/(mol·cm),汞浓度在O～1.2μg/mL符合比耳定律。该方法用于饮料样品中微量汞的测定,精密度(RSD)为1.6%～2.3%,回收率为98.0%～101.2%。无需分离、简便快速。     

Development and Validation of a Green High Performance Liquid Chromatographic Method for the Determination of Some Artificial Sweeteners and Caffeine in Soft Drinks

A simple and green high performance liquid chromatographic method was developed to determine the acesulfame K, saccharin, aspartame, and caffeine content in soft drinks without the use of toxic organic solvents. Separation was carried out on a C18 column using ethanol–phosphate buffer as the mobile phase at 0.8 mL/min. Optimum separation was achieved in 15 min. Acesulfame K, saccharin, aspartame, and caffeine were detected at 225, 217, 217, and 280 nm, respectively. The calibration curves were linear (correlation coefficient ≥0.999) in the selected range of each analyte. The limit of detection was 0.024 mg/L for acesulfam K, 0.011 mg/L for saccharin, 0.024 mg/L for caffeine, and 0.014 mg/L for aspartame. The relative standard deviations in inter and intra-laboratory precision studies varied from 0.44% to 1.61%. Recoveries of the analytes from spiked diet cola samples were between 98.40% and 100.25%. The validated method was found to be accurate and precise in the working calibration range. The developed analysis method was applied to 56 soft drink samples and was statistically compared with a conventional method by using test material. In conclusion, the developed HPLC analysis method provided more accurate values than the conventional analysis method.     

PVC薄膜味觉传感器阵列对调味品和软饮料的识别

以铂工作电极(PtE)为基底聚合吡咯(PPy),并在聚吡咯表面被覆不同味敏剂修饰的PVC薄膜,得到八支味觉传感器,并进而与217型双盐桥饱和甘汞电极构成味觉传感器阵列-8-PPP-TSA。采用开路电位法获取调味品和软饮料不同样品在各传感器界面的数据响应矩阵,数据矩阵使用主成分分析方法可将各样品属性的相似相异程度在二维得分图上得以直观表达,调味品被分为鲜、咸-鲜、咸、酸四个区,软饮料被大致分为甜、高酸低甜、高甜低酸三个区;根据各样本之间的欧氏距离大小,使用聚类分析方法作亲疏关系树形谱系图,在不同的相似度下可将众多样品依据亲疏关系远近进行有层次的味觉聚类区分,错判较少。此外,模式识别分析结果表明,8-PPP-TSA的仿生味觉识别具有与生物味觉识别相似的特点。     

Development of a Headspace-Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (HS-SPME-GC/MS) Method for the Determination of Benzene in Soft Drinks

A method based on headspace-solid phase microextraction and gas chromatography with mass spectrometry has been developed and validated for the determination of benzene in soft drinks. The extraction step was optimized using a rotatable central composite design including the following experimental variables: extraction temperature, extraction time, sample weight, and salt concentration. The optimized procedure, which was carried out at 30 °C during 30 min by using a 75 μm carboxen-polydimethylsiloxane fiber, showed good linearity within the concentration range 0–25 μg?kg^?1 (r ² ?>?0.999), mean recoveries from 97.5 to 103.1 %, and coefficients of variation from 1.5 to 13.4 % for repeatability and from 1.5 to 15.7 % for within-laboratory reproducibility. Limits of detection and quantification were calculated at 0.02 and 0.08 μg?kg^?1, respectively. The method was applied to determine the concentrations of benzene in 77 samples of beverages from the Brazilian market. Levels from <0.08 to 10.84 μg?kg^?1 were obtained, which are comparable to those verified in other countries. Most of the samples (72.2 %) contained benzene up to 1 μg?kg^?1.     

石墨烯电化学传感器法快速测定植物油中的苯并（a）芘

利用新型纳米材料石墨烯与聚合物材料壳聚糖构建纳米电化学传感器,研究苯并（a）芘（benzo(a)pyrene,BaP）的电化学性质,并建立一种植物油中BaP的快速灵敏检测方法。BaP在该纳米电化学传感器上的循环伏安图表明在1.0?V处出现了一个形状良好的氧化峰,无还原峰,为一种不可逆的氧化还原过程;优化纳米电化学传感器法快速测定植物油中BaP的实验条件,结果表明：壳聚糖-石墨烯（1∶2,V/V）混合溶液作为修饰液,修饰量5?μL、电解质LiClO4浓度0.2?mol/L、硫酸浓度0.1?mol/L、富集时间15?min,在此条件下,BaP的氧化还原峰电流与其浓度在0～100?nmol/L之间具有良好的线性关系,校正曲线方程为：Ip=0.116?2CBaP＋22.926?2（R2=0.997?8）,其检测限为0.103?nmol/L（RSN=3）。利用该法对香油样品中的BaP进行检测,其加标回收率为98.51%～100.57%,检测结果与高效液相色谱法基本一致,并且具有良好的稳定性和重复性,样品预处理简单、检测时间短、速度快、成本低。     

新兴的饮料行业将是在新世纪成长性最快的行业

我国饮料工业是改革开放以后发展起来的新兴行业,近20年来一直保持高速发展。饮料总产量由1980年的28.8万吨猛增到1999年1168万吨,年均增长率超过20%。目前国内饮料的年生产能力已达到2000万吨。饮料行业已从根本上改变了直至80年代末还是碳酸饮料一统天下的局面,品种已发展到包括碳酸饮料、果蔬汁饮料、瓶装水饮料、茶饮料、植物蛋白质饮料、含乳饮料、功能性饮料等在内的10大类型,一些新型饮料的产量正在声速增长,极大丰富了饮料市场。     

高效液相色谱法测定蛋卷中的苋菜红和日落黄

建立了测定蛋卷中合成色素日落黄和苋菜红的高效液相色谱分析方法.蛋卷中的合成色素经聚酰胺吸附提取,制成水溶液,过滤后用高效液相色谱仪测定.采用ODS柱分离,甲醇和乙酸铵溶液(0.02 mol/L)为流动相,测定蛋卷中苋菜红和日落黄,结果的相对标准偏差为1.5 %～5.9 %,实际蛋卷样品的回收率为71.5 %～81.4 %,检出限均为0.5 mg/kg.     

快速检测痕量镉的光电型传感器的建立

利用1-4-(硝基苯)-3-(3-甲基吡啶)三氮烯与镉络合显色的原理,将1-4-(硝基苯)-3-(3-甲基吡啶)三氮烯固定化制成试纸条,插入自制的便携式单色光反射计,组装出检测镉的光电型传感器。结果表明:当镉浓度范围为0.0179～0.2857mmol/L时,光反射率与镉浓度呈现良好的线性关系。优化检测条件后,该方法的检出限为0.00348mmol/L,检测时间为2min。此种方法检测镉所需时间短、操作简便,有望实现镉的现场检测。     

基于碳纳米管组装电化学传感器测定金丝桃苷的含量

目的:采用单壁碳纳米管(SWCNTs)修饰玻碳电极(GCE),制作电化学传感器,研究金丝桃苷在传感器表面的电化学行为,建立一种简单的、高灵敏的金丝桃苷的电化学检测新方法。方法:将羧基化SWCNTs滴在GCE表面,采用循环伏安法(CV)研究了金丝桃苷在传感器表面的电化学行为,并对测量条件进行了优化。结果:和裸GCE电极相比较,金丝桃苷在GCE/SWCNTs电极表面的氧化峰电流和还原峰电流均急剧增加,氧化峰电流和还原峰电流与扫描速度的平方根成正比,说明金丝桃苷在修饰电极表面的反应是受扩散控制的过程。在缓冲液的pH为6.0、碳纳米管的用量为10 μL、检测电位为0.34 V的优化条件下时,金丝桃苷浓度在3.0×10^-9~1.0×10^-7范围内与氧化电流呈现良好的线性关系,检出限为2.41×10^-9 mol/L(S/N=3)。结论:该方法灵敏度高,简单易行,具有较好的重现性及稳定性,可用于金丝桃苷的检测。     

基于混合气凝胶负载银纳米粒子构建电化学传感器用于食品过氧化氢的测定

以聚多巴胺为“胶联剂”将羧基碳纳米管和被透析的氧化石墨烯通过氨基、羧基等基团键合形成3 维分层多孔结构的混合气凝胶,并以混合气凝胶为基底原位负载银纳米粒子,建立一种有效检测食品中过氧化氢的电化学方法。最佳条件为pH 7.4、工作偏压－0.4 V、电极修饰液体积5 μL,以AgNPs-MAs修饰电极为工作电极对过氧化氢的响应电流是裸玻碳电极的24.5 倍。采用计时电流法快速、灵敏检测过氧化氢,其峰电流与浓度呈良好线性关系,其线性方程为I＝0.32c＋1.66（相关系数0.999 3）,检出限0.02 μmol/L（信噪比3）。此外,该传感器具有较高的准确性、稳定性和抗干扰性,能实现重复利用。该传感器应用于牛奶中过氧化氢的测定,回收率为98.1%～98.8%,相对标准偏差为0.58%～2.28%,有望应用于食品中过氧化氢的快速、痕量检测。     

Determination of Bisphenol A and Alkylphenols in Soft Drinks by High-Performance Liquid Chromatography with Fluorescence Detection

A highly sensitive and selective method was developed for the purification and determination of bisphenol A and alkylphenols in soft drinks by using 2-(11H-benzo[a]carbazol-11-yl) ethyl chloroformate (BCEC-Cl) as pre-column labeling reagent followed by high-performance liquid chromatography (HPLC) with fluorescence detection. The HPLC sensitivity of bisphenol A and alkylphenols was greatly enhanced through the introduction of BCEC-Cl moiety with excellent fluorescence property into the target molecules. Meanwhile, the introduction of highly hydrophobic BCEC-Cl moiety into the analytes also greatly increased the hydrophobicity of the target compounds and distinguished them from hydrophilic matrices. Therefore, little interference was observed. Solid-phase extraction with C18 cartridges was applied to sample purification procedure with recoveries of higher than 82 %. When 20 mL of sample was used for analysis, the limits of quantifications of the analytes were between 0.06 and 0.1 μg?L^?1. The proposed method was successfully applied to the determination of the target compounds in soft drink samples with a much higher sensitivity than traditional HPLC methods.     

分光光度法测定混合酸性染料溶液中各染料浓度

对九组由不同结构酸性染料以不同比例两两拚混的染液进行了分光光度法测定，并把测定值与实配值进行了对比     

可再生电化学传感器同步检测贝类中痕量铅和镉

目的：针对贝类中高毒重金属铅（Pb）和镉（Cd）,开发一种可再生、廉价、快速、灵敏的电化学传感器。方法：以自制离子液体/石墨烯电极（IL/GNs HME）为工作电极,采用微分脉冲阳极溶出伏安法（DPASV）原位镀铋,根据得到的溶出峰电流,实现对Pb2+和Cd2+的同步测定。结果：在铋离子质量浓度500 μg/L,富集时间420 s,搅拌速度600 r/min,富集电压-1.1 V,缓冲体系HAc-NaAc pH 4.2的条件下,利用电化学传感器测得的Pb2+和Cd2+的线性范围均为1.0~45.0 μg/L,检测限分别达0.5 μg/L和0.8 μg/L。采用IL/GNs HME电化学传感器同时检测扇贝、褶牡蛎、长竹蛏、菲律宾蛤子中Pb2+、Cd2+含量时,所得结果均与电感耦合等离子体质谱（ICP-MS）检测结果相符。结论：基于IL/GNs HME构建的电化学传感器操作简便、灵敏度高,可实现对贝类中Pb2+、Cd2+含量的快速、同步测定。