反相高效液相色谱法测定蓝藻中的微囊藻毒素

经稀酸提取和固相萃取柱富集微囊藻毒素(MC)后,采用反相高效液相色谱测定蓝藻水华中的MC-RR-、YR-、LR。考察了在300SBZorbax C18柱(250×4.6 mm i.d.,5μm)上流动相中乙腈含量、三氟乙酸浓度以及温度对分离的影响。在等度及梯度洗脱条件下,三种毒素均被完全分离,梯度洗脱时峰形更好,检测灵敏度较高。方法对蓝藻干粉中MC的检出限为20 ng/g,线性范围为0.06~6μg/g,回收率91.7%~102.1%。此方法灵敏度高,实用性强,可作为水质藻毒素风险评价和监测蓝藻脱毒效能较可靠的分析方法。     

柱前衍生-高效液相色谱法测定茶叶中的黄曲霉毒素B1

应用柱前衍生-高效液相色谱法测定茶叶中黄曲霉毒素B1的含量。样品采用乙腈(85+15)溶液提取,滤液用MycoSepTM226柱净化,加入正己烷和三氟乙酸衍生,经C18色谱柱分离,荧光检测器检测。黄曲霉毒素B1的质量浓度在0.20~10.0μg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.1μg·kg-1。在0.5,1.0,5.0μg·L-1等3个浓度水平进行加标回收试验,回收率在91.9%~102%之间,测定值的相对标准偏差(n=6)在1.5%~6.9%之间。     

高效液相色谱法测定奶粉中黄曲霉毒素M1的不确定度评定

利用高效液相色谱法测定奶粉中黄曲霉毒素M₁含量,对测定结果的不确定度进行评定。通过实验步骤和定量方法建立数学模型,分析不确定度来源,计算合成不确定度和扩展不确定度。结果表明,标准溶液配制、重复性测量、样品处理对测定结果的不确定度贡献较大。在实际工作中,可以通过选择A级标准玻璃器具、优化样品处理方法、重复测定样品来减小结果的不确定度,提高检测结果的准确性。当样品中黄曲霉毒素M₁的质量分数为0.522 μg/kg时,其扩展不确定度为0.027 μg/kg(k=2)。     

高效液相色谱法测定牛奶中黄曲霉毒素M1含量的不确定度评定

根据方法GB 5009.24-2016《食品安全国家标准食品中黄曲霉毒素M族的测定》,建立高效液相色谱法测定牛奶中黄曲霉毒素M₁含量不确定度的数学模型,分析检测过程中的不确定度来源,并对不确定度分量进行量化和合成.当牛奶中黄曲霉毒素M₁的质量分数为0.842 μg/kg时,其扩展不确定度为0.048 4 μg/kg（k=2）.方法相对不确定度主要来源于标准品纯度和样品回收率.     

高效液相色谱法检测人肝组织中黄曲霉毒素

以人肝癌组织为研究材料,丙酮、氯仿为主要抽提溶剂,建立了用高效液相色谱技术检测肝组织中黄曲霉毒素Ｂ＿１的方法。采用μ－Ｐｏｒａｓｉｌ色谱往,氯仿、环己烷、乙腈、异丙醇为流动相,荧光检测器检测,激发波长３６５ｎｍ,发射波长４３５ｎｍ。方法的平均回收率为９６．８５％,变异系数为４．５２％,最低检测限为０．０５ｎｇ。１０例肝癌组织中有７例检出５。４９～７３．７０ｎｇ／ｇ不等的黄曲霉毒素Ｂ＿１。方法快速、准确、灵敏度高。     

反相高效液相色谱法测定阿莫西林

采用反相高效液相色谱法测定阿莫西林并对测定条件及有关参数进行了试验.用Shim-Pack VP-ODS柱作色谱柱,以磷酸盐缓冲液(pH 5.0)及乙醇以90比10的混合液为流动相,流速为1.0 mL·min-1,在228nm波长处测定阿莫西林的含量,其线性范围为0.045～0.60 g·L-1,相关系数为0.9974.将方法应用于阿莫西林胶囊的测定,测定结果的相对标准偏差值小于0.6%,用标准加入法作回收试验,回收率结果在94.7%～101.3%之间.     

反相高效液相色谱法测定罗布麻叶中的绿原酸

采用反相高效液相色谱法(RP-HPLC)在ODS Hypersil(5μm,125 mm×4mm i.d.)色谱柱上以甲醇、体积分数2%HAc为流动相测定了罗布麻叶中的绿原酸。流动相的流速为0.6 mL/min,检测波长为328 nm,建立了回归方程y=11071.10V-27.06,r=0.9999,绿原酸的回收率为98.54%。     

QuEChERS提取-高效液相色谱法测定泰山虫草中4种黄曲霉毒素的含量

取泰山虫草样品2.50g,加入7.5mL水和含0.1%(体积分数)乙酸的乙腈混合溶液10mL,涡旋振荡1min,再加入无水硫酸镁4.0g和氯化钠1.0g,离心,取上清液1.0 mL于含150mg无水硫酸镁、50mg N-丙基乙二胺、50mg C18填料、12mg石墨化碳黑的2mL分散固相萃取管中,涡旋振荡30s,取上清液经过0.22μm有机滤膜进行过滤,采用高效液相色谱法测定其中4种黄曲霉毒素的含量。结果表明:4种黄曲霉毒素的质量浓度在一定范围内与其峰面积之间呈线性关系,检出限(3S/N)在0.06～0.20μg·kg-1之间。按照标准加入法进行加标回收试验,测得回收率在92.4%～102%之间,测定值的相对标准偏差(n=6)在2.7%～3.5%之间。     

反相高效液相色谱法测定肿瘤细胞腺苷酸

测定肿瘤细胞中的腺苷酸类,可了解肿瘤细胞能量异常代谢,同时在研究抗肿瘤药物的作用机理方面具有重要的意义。核苷酸类化合物具有很强的水溶性,用反相色谱法分离效果比离子交换色谱法更好,其优点是色谱柱易于平衡,结果的重复性好。本文在Schweinsberg测定红细胞方法的基础上,对梯度曲线及分析时间进行合理的调整和改进,并利用此方法测定了Hela细胞株和L_(78M)腹水白血病细胞腺苷酸类。     

超高效液相色谱法快速测定发酵茶叶中的黄曲霉毒素

建立了用超高效液相色谱/紫外检测器测定发酵茶叶中黄曲霉毒素B1、B2、G1和G2的方法.用CH2Q2提取黄曲霉毒素,提取液经浓缩后,用LC-CN固相萃取小柱净化,超高效液相色谱测定.在浓度范围20～200μg/L(B1、G1),15～120μg/L(B2、G2)内具有良好的线性相关关系.黄曲霉毒素的回收率为81.4%～92.3%,相对标准偏差RSD 1.6%～4.2%.检出限为0.32μg/kg(B1、G1),0.18μg/kg(B2、G2)(S/N=3).     

Determination of Aflatoxin M1 in Milk by a Magnetic Nanoparticle-Based Fluorescent Immunoassay

A sensitive and rapid magnetic nanoparticle-based fluorescent immunoassay for the determination of aflatoxin M1 in raw milk was developed. Aflatoxin M1 was converted to aflatoxin M1-o-carboxymethyl oxime. The aflatoxin M1-oxime was used for the preparation of aflatoxin M1-oxime-fluoresceinamine conjugate through the carbodiimide reaction. The aflatoxin M1-oxime-fluoresceinamine conjugate was characterized by ultraviolet–visible and infrared spectroscopy. Magnetic nanoparticles (Fe₃O₄) were synthesized and modified by 3-(aminopropyl)triethoxysilane. The size of initial (139?nm) and functionalized magnetic nanoparticles (147?nm) was determined by particle analysis. The optimal mass of immobilized antibody (25?µg) and optimal concentration of aflatoxin M1-oxime-fluoresceinamine conjugate (15?µg?mL^?1) for magnetic nanoparticle-based fluorescent immunoassay were determined. The developed immunoassay provided a linear aflatoxin M1 concentration range from 3.0 to 100?pg?mL^?1 in bovine milk. The detection limit was 2.9?pg?mL^?1. The results of aflatoxin M1 magnetic nanoparticle-based fluorescent immunoassay in heat-treated milk and phosphate-buffered saline at pH 6.6 were compared. The influence of the somatic cell count, pH, and fat concentration in bovine milk on the aflatoxin M1 immunoassay was investigated. The influence of the milk species on the immunoassay was also characterized. The high fat concentration ovine milk depressed the sensitivity of the aflatoxin M1 immunoassay.     

Molecular Recognition of Aflatoxin M1 in Water and Milk Samples

Two stochastic microsensors based on diamond paste modified with 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) were proposed for the molecular recognition of aflatoxin M1 in water and milk samples. Two types of diamond were used: a monocrystalline diamond powder (1 μm) (DP) and a nanopowder of monocrystalline diamond (10 nm) (nDP) for the design of the stochastic microsensors. The microsensors were incorporated as combined stochastic microsensors (a microcell containing the stochastic microsensor and the Pt wire, and a Ag/AgCl sensor) in a platform used for monitoring of waste waters and milk samples. The platforms were used for the fast screening of water and milk samples for the qualitative and quantitative analysis of aflatoxin M1 at very low concentration levels (up to 0.001 fg/L). The linear concentration ranges were wide, being able to cover concentrations between 0.001 fg/L to 20 μg/L. The highest sensitive microsensor (sensitivity of 4.74×10¹⁰ s mg^?1 L) was the one based on nDP. The results provided by the platforms were in agreement with those obtained by utilization of standard method (ISO certified methods (HPLC/fluorescence method)), recoveries being higher than 99.00 % and RSD lower than 1.00 % proving that the method can be reliable used for molecular recognition of aflatoxin M1 in water and milk samples.     

液相色谱串联质谱法快速测定牛奶与鸡蛋中的维吉霉素M_1残留量

建立了牛奶和鸡蛋样品中维吉霉素M_1残留的液质联用确证方法.用乙腈萃取样品中的维吉霉素M1残留,水稀释后,正己烷脱脂,以YMC-Pack Pro C_(18)色谱柱为分离柱,在正离子模式下以电喷雾电离串联质谱仪进行测定.方法的线性范围为2.5 ～25 μg/L,定量下限为50 μg/kg.在50、100、200 μg/kg 3个浓度水平进行加标回收实验,回收率为72% ～99%,相对标准偏差为2.7% ～6.1%.该方法简便、快速、准确,各项技术指标满足国内外法规的要求,可用于牛奶和鸡蛋样品中维吉霉素M1残留的快速确证检测.     

反相高效液相色谱法测定抗氧化剂硫代二丙酸双十二醇酯

提出了用反相高效液相色谱法测定抗氧化剂硫代二丙酸双十二醇酯(DLTDP)含量的方法。采用Symmetry C18色谱柱,甲醇-水(98+2)为流动相,示差折光检测器,外标法定量,抗氧化剂DLTDP的质量浓度在0.20~20.0 g·L-1范围内与峰面积呈线性关系,测定下限(10S/N)为0.10 g·L-1。应用此方法分析了5批DLTDP样品,测得其DLTDP的质量分数在95.6%~99.3%之间,测定值的相对标准偏差(n=5)均小于1.1%。     

反相高效液相色谱法测定合成反应产物中溴代硝基芴酮

提出了用反相高效液相色谱法测定合成溴代硝基芴酮类化合物的反应产物中2,7-二溴-4-硝基芴酮(DBNFN)的含量。样品用甲醇作溶剂超声溶解,以Elite Hypersil ODS2C18色谱柱及甲醇-水(85+15)混合溶液作流动相进行分离。在所选择的条件下可达到DBNFN与共存物2,7-二溴芴酮(合成所用原料)和芴酮衍生物(副产品)三者之间的完全分离。采用紫外检测(波长254nm)和外标法定量。DBNFN的质量浓度在0.1～2.5g.L-1范围内与其峰面积呈线性关系。方法的检出限(2S/N)为3.8μg.L-1。用标准加入法做回收试验,测得回收率在99.2%～99.8%之间,测定值的相对标准偏差(n=6)在0.35%～0.48%之间。     

一种简单灵敏的基于适配体的黄曲霉毒素B1电化学传感器

黄曲霉毒素B1（AFB1）以其高毒性和致癌性成为食品安全隐患而备受关注. 本文拟构建一种新颖、简单、快速、灵敏的传感器用于谷物食品中AFB1的痕量检测. 将介孔碳（CMK）修饰在工作电极表面来增大电极的表面积,再将工作电极恒电位沉积金纳米粒子（AuNPs）,提高电信号的同时,为下一步巯基化适配体的连接提供位点. 检测过程中,AFB1可以竞争性地去除吸附在适配体链上的亚甲基蓝（MB）引起电信号的变化,对AFB1进行定量检测. 修饰的工作电极导电性能得到改善,灵敏度大大提高,对AFB1的线性响应范围为0.1 ~ 75 μg·L^-1,检出限低至36 ng·L^-1. 在对不同谷物食品（大米、玉米、糯米）进行加标回收实验中,回收率在92.3% ~ 103.6%范围之间,实现对目标物的定量检测. 本文为食品中AFB1快速检测方法提供了一种新思路和新方法.     

反相高效液相色谱法测定豆制品中两种异黄酮甙元的含量

建立了反相高效液相色谱测定异黄酮甙元的方法。采用Hypersil BDS C18色谱柱(250×4.6 mm i.d.,5μm),流动相为甲醇(A)、0.5%乙酸水溶液(B),流速为1.0mL/min,柱温为35℃,检测波长为260 nm,进样量为10μL。结果表明:大豆黄素的线性范围为0.0450~0.3150μg,加标回收率为99.05%,相对标准偏差(RSD)为1.31%;染料木黄酮的线性范围为0.0448~0.3136μg,加标回收率为98.82%,RSD为0.50%。方法可用于豆豉及其它大豆制品中异黄酮甙元的测定。     

Novel Enzyme-Linked Aptamer Assay for the Determination of Aflatoxin B1 in Peanuts

Abstract

A novel enzyme-linked aptamer assay is reported for the determination of aflatoxin B₁ (AFB₁). AFB₁ can competitively bind with the immobilized biotin-aptamer and release biotin complementary DNA, leading to the gradual fading of the detection system color with increasing of AFB₁ concentration. In the absence of AFB₁, the biotinylated complementary DNA is not be released from the fixed aptamer. Therefore, the enzyme reaction occurs in the detection system. Under the optimized experimental conditions, the proposed method possessed a wide linear range for AFB₁ from 1 to 80?ng/mL (R² of 0.990) with a low detection limit of 0.36?ng/mL. The method was then applied to detect uncontaminated peanuts fortified with different concentrations of AFB₁. The recovery values were from 82.60% to 94.43%, which indicated the proposed method may be used to detect AFB₁ in food and has potential for the development of test kits.