CdS修饰玻碳电极电化学发光法检测三聚氰胺

本文将CdS纳米棒修饰到玻碳电极上制作了CdS修饰玻碳电极(CdS/GCE)并研究了其在K2S2O8溶液中的电化学发光(ECL)性能.基于三聚氰胺能淬灭CdSK2s2O8电化学发光的性质建立了一种检测三聚氰胺的方法.在最优条件下,体系的ECL强度与三聚氰胺浓度在1.0×10-9～1.0×10-7 mol/L范围内与EC...     

三聚氰胺分析检测方法的研究进展

介绍了三聚氰胺的物理和化学性质、用途,及其作为食品添加剂对人体健康的危害;重点总结了三聚氰胺现有的各种检测方法;并就各种检测方法的优劣进行了比较.指出三聚氰胺是一种工业原料,而在食品中添加三聚氰胺会危害人们的身体健康,甚至致人死亡;正因为如此,三鹿奶粉事件的发生为社会敲响了警钟,引起了人们对三聚氰胺及其衍生物的普遍关注.     

高效液相色谱法检测水产品中三聚氰胺的残留量

建立了水产品肌肉组织中三聚氰胺的高效液相紫外检测法.肌肉组织中加入三氯乙酸作为提取剂,乙酸铅沉淀蛋白,过PCX混合阳离子交换柱净化等样品处理过程;乙腈-10 mmol庚烷磺酸钠+10 mmol柠檬酸溶液 (8∶92,V/V)为流动相,紫外检测波长为240 nm.方法在0.100～10.00 mg/L浓度范围内呈线性相关,相关系数r=0.999 9.平均回收率为74.29%～ 89.04%,相对标准偏差为0.44%～9.32%,三聚氰胺在水产品肌肉中的检测限为0.1 mg/kg.方法适用于水产品肌肉组织中三聚氰胺残留量的检测.     

喷射式电化学发光流动检测技术快速测定奶粉及液态奶中三聚氰胺

采用喷射式电化学发光流动检测技术建立了奶粉和液态奶中三聚氰胺检测的新方法。在优化条件下,三聚氰胺浓度的负对数在1.0×10-9～1.0×10-3g/L范围内与其电化学发光强度呈良好的线性关系,检出限(S/N=3)为1.0×10-9g/L。不同加标量的阴性样品加标回收率为92.2%～114.2%,相对标准偏差为0.46%～1.2%。该方法具有检测灵敏、操作简单、样品用量少等优点,有望用于三聚氰胺的现场快速检测。     

核酸适配体生物传感器在三聚氰胺检测中的应用进展

三聚氰胺常被非法添加到食品中,以提高食品中蛋白质的含量。但是,三聚氰胺一旦进入体内,会对人们的健康造成伤害。因此,对三聚氰胺的检测十分必要。为了弥补传统仪器检测法和免疫检测法的不足,基于核酸适配体开发了一系列新的生物传感器,用于三聚氰胺的检测。按照与三聚氰胺的不同识别机制,把这些新的生物传感器分成了四类,分别为基于多聚胸腺嘧啶DNA链和三聚氰胺识别的生物传感器、基于无嘌呤位点的三链DNA结构和三聚氰胺识别的生物传感器、基于核酸适配体和三聚氰胺识别的生物传感器、基于三聚氰胺和汞离子/铜离子等配位识别的生物传感器。本文按照上述四类方法逐个展开,对核酸适配体生物传感器在三聚氰胺检测中的应用进行了综述,并对它们的优缺点进行阐述。     

高效液相色谱法测定鸭肉中的三聚氰胺

采用反相高效液相色谱法测定了鸭肉中的三聚氰胺.Diamonsil C18柱,流动相:V(乙腈)∶V(4 mmol/L己烷磺酸钠水溶液)=5∶95,乙酸调pH为3.3;检测波长240 nm.在0.25～40 mg/L范围内线性关系良好,相关系数R=0.9999.方法检出限0.056 mg/kg,回收率在80%～86%之间,相对标准偏差小于2.55%.     

高效液相色谱法测定腐竹中的三聚氰胺

建立了腐竹中三聚氰胺的高效液相色谱检测方法.样品经0.1 mol/L的盐酸溶液提取,亚铁氰化钾和乙酸锌沉淀蛋白,以0.05 mol/L磷酸二氢钾溶液(pH 3.0)-乙腈为流动相,300-SCX离子交换色谱柱分离,二极管阵列检测器于波长240 nm处进行检测.该方法线性范围为0.1～5 μg/mL,检出限为2.0 mg/kg,测定结果的RSD为1.3%～2.5%(n=6),加标回收率为85.8%～92.1%,方法能够满足检测要求.     

固相萃取-液相色谱-串联质谱法检测食品中的三聚氰胺

样品经均质,1%三氯乙酸溶液提取,用OASIS MCX固相萃取小柱净化,减压浓缩后以甲醇溶解定容,用Waters BEH-C8柱分离,乙腈和水为流动相,经液相色谱-串联质谱法检测.三聚氰胺线性范围为0.1～10.0mg/kg,相关系数r为0.9999,平均回收率为71%～95%,相对标准偏差为4.56%～9.82%(n=6),方法的栓出限为0.5 mg/kg.     

气相色谱-质谱法测定鸡蛋中三聚氰胺

建立了气相色谱-质谱法测定鸡蛋中三聚氰胺的方法. 鸡蛋样品经三氯乙酸提取,乙酸铅沉淀蛋白后,过MCX阳离子交换固相萃取小柱除去样品基质干扰,用N,O-双三甲基硅基三氟乙酰胺(BSTFA)+三甲基氯硅烷(TMCS)(99+1)衍生,进行气相色谱-质谱分析. 在0.010~2.00 mg/L浓度范围内,线性关系良好(r=0.9996),检出限为0.01 mg/kg. 方法回收率为90.1%~94.7%,RSD为1.7%~5.3%. 方法准确、灵敏,适用于鸡蛋中三聚氰胺的检测.     

液相色谱法测定大豆分离蛋白中的三聚氰胺

建立了大豆分离蛋白中三聚氰胺的液相色谱方法。大豆分离蛋白经过1%三氯乙酸和饱和乙酸铅溶液提取后,经过阳离子交换固相萃取柱净化处理,用5%氨化甲醇洗脱,洗脱液用高效液相色谱紫外检测器检测,外标法定量。三聚氢胺的质量浓度在0.4~40 mg/L范围内与色谱峰面积呈良好的线性关系,相关系数为0.9990。方法的检出限为0.6 mg/kg,定量限为2 mg/kg。2,4,20 mg/kg 3个浓度水平的加标回收率在78.82%~92.95%范围内。该方法分析成本低,测定结果准确,能满足常规检测及食品安全监控的需要。     

Electrochemical Detection of Melamine

Poly(caffeic acid) polymer was immobilized onto the surface of a glassy carbon electrode via electropolymerization. Voltammetry shows a signal related to the two‐electron oxidation of the immobilized hydroquinone groups in the caffeic acid monomer units. The modified electrode in aqueous solution shows complexation of the electrogenerated o‐quinone species with melamine thus allowing in the electrochemical detection of melamine by recording the shift in potential of the oxidation signal of the polymer. Melamine detection was investigated in pure aqueous solutions and in the presence of milk powder solutions and the proposed analytical method of melamine detection in milk powder was applied successfully with an average recovery of ca. (91±7.9)%.     

三聚氰胺泡沫塑料的研究进展

三聚氰胺泡沫塑料是一种具有良好阻燃、隔音和保温性能的新型材料。本文主要介绍了三聚氰胺泡沫塑料的制备工艺和应用性能,并对其未来发展趋势进行了展望。     

Determination of Melamine in Food by SPE and CZE with UV Detection

A novel method for the determination of melamine residue in food was developed using solid-phase extraction and capillary zone electrophoresis with UV detection. Spiked samples were extracted with 1% trichloroacetic acid while 0.03 g sodium deoxycholate was used to precipitate protein in the real samples. After centrifuging and clean-up by solid-phase extraction cartridge, the extract was directly analyzed by CZE–UV. The method was validated and good results were obtained with respect to precision, repeatability and spiked recovery. The limit of detection for melamine varied between 0.25 and 0.5 mg kg^?1. The proposed method was successfully applied for the analysis of melamine in food with total recoveries ranging from 94 to 102% in the spiked range of 0.5–5 mg kg^?1, and the relative standard deviations were between 1.5 and 4.1%.     

奶粉中三聚氰胺等伪蛋白的危害和新检测方法

2008年9月,中国爆发了“三鹿”婴幼儿奶粉受污染事件,导致不少食用受污染奶粉的婴幼儿产生肾结石病症,甚至引发了危及生命的严重并发症。国家质检总局对此事进行了系统的调查,结果表明,事件的主要原因在于奶粉中含有三聚氰胺,长期食用这些高含量三聚氰胺的奶粉危害了婴幼儿的健康,这就是震惊中外的“三聚氰胺事件”。     

Detection of Melamine in Powdered Milk Using Surface-Enhanced Raman Scattering with No Pretreatment

We detected a trace amount of melamine in powdered milk using surface enhanced Raman scattering (SERS) on gold surfaces at an excitation wavelength of 632.8 nm. A detection limit of ～100 ppm (μg/g) melamine in milk was attained within a few minutes by the gold nanoparticle substrate from chemical reduction; whereas, better sensitivity, as low as ～200 ppb (ng/g), was achieved by the roughened gold substrate. Our method has the advantage of fast and sensitive detection of melamine in powdered milk without pre-treating the samples.     

Melamine contamination

In the summer of 2008, serious illnesses and deaths of babies in China were linked to melamine-tainted powdered infant formula. Melamine contains several metabolites, such as ammeline, ammelide, and cyanuric acid, and has been used for the adulteration of foods or milk to increase their apparent protein content. It is assumed that melamine and its metabolites are absorbed in the gastrointestinal tract, and precipitate in the kidney to form crystals. A new tolerable daily intake of 0.2 mg kg^?1 body weight was adapted by the World Health Organization in 2008. This paper reviews the variety of analytical methods that have been used for the analysis of melamine in food. The limit of detection of these various methods is 0.05–100 ppm. The maximum acceptable concentration in food has been set at 50 ppb by the US FDA. A fast and ultrasensitive procedure for screening, detection, and characterization of melamine and its derivative compounds needs to be established. Currently, mass-spectrometry technologies provide an alternative to derivatization for regulatory analysis of food.     

基于对荧光铜纳米簇合成的抑制检测三聚氰胺

三聚氰胺能与铜离子(Cu2+)形成配合物,对荧光铜纳米簇的合成有明显抑制作用,且其抑制程度与三聚氰胺浓度在一定范围内呈线性关系.基于此构建了一种简单、快速检测三聚氰胺的方法.以聚T单链DNA为模板合成的铜纳米簇作为荧光探针,当三聚氰胺存在时,Cu2+与三聚氰胺生成配合物,阻碍铜纳米簇的合成,导致荧光强度降低.在优化的实验条件下,三聚氰胺浓度在5~120 μmol/L范围内呈良好的线性关系,检出限为1.5 μmol/L,牛奶样品中三聚氰胺加标回收率为96.3%~104.4%.与传统纳米金/银、量子点等方法相比,本方法具有简单、快速、灵敏等优点.     

2-硫代巴比妥酸修饰金纳米探针高灵敏比色检测三聚氰胺

以2-硫代巴比妥酸(TBA)修饰金纳米粒子为探针,TBA与三聚氰胺通过氢键作用诱导金纳米探针团聚,进而使金纳米胶体颜色由酒红色变为蓝色。 实验优化得最佳反应条件为在乙酸缓冲溶液（pH=7.0）介质中,室温反应15 min。 对不同浓度三聚氰胺进行检测时发现,在0.062~0.18 μmol/L和0.18~6.0 μmol/L之间,A660/A520吸收比率与三聚氰胺浓度呈现良好的线性关系,检出限为0.043 μmol/L。 该方法用于检测牛奶样品中的三聚氰胺的加标回收率为102.8%～105.3%。     

A Sensitive Electrochemical Approach for Melamine Detection Using a Disposable Screen Printed Carbon Electrode

We report here a simple and easy electrochemical approach for sensitive detection of non‐electroactive melamine using a disposable screen printed carbon electrode (SPCE) with uric acid as the recognition element. It is based on the competitive adsorptive behavior of melamine at the preanodized SPCE causing suppression in the oxidation current of uric acid. A linear range up to 126 ppb with a detection limit of 1.6 ppb (S/N=3) is achieved at the preanodized SPCE by differential pulse voltammetry. The electrochemical method is successfully applied to detect the melamine content in tainted milk powder and dog food.