莱克多巴胺荧光胶乳颗粒免疫层析检测法的建立

基于免疫竞争层析法原理,建立了莱克多巴胺(RAC)的荧光胶乳颗粒免疫层析快速检测技术,用于猪肉组织中莱克多巴胺残留的检测.应用自制的抗RAC单抗,标记己胶乳荧光颗粒,将标记好的复合物喷涂于结合垫上.羊抗鼠IgG与人工合成的RAC - BSA检测抗原包被在NC膜表面,分别作为质控线(C线)与检测线(T线).检测过程中RA...     

多壁碳纳米管净化/超高效液相色谱串联质谱同时测定动物组织中四环素与喹诺酮多残留

采用超高效液相色谱-串联质谱(UPLC-MS/MS)在正离子模式下通过多反应监测(MRM)方式同时测定了猪肉和鸡肉中3种四环素和2种喹诺酮类药物的残留量.残留药物经Mcllvaine-Na2EDTA缓冲溶液(pH4.0)提取后,采用多壁碳纳米管(WMCNTs)固相萃取柱净化,甲酸-乙腈(体积比5:95)洗脱,UPLC-...     

Mimic Pork Rinds from Plant-Based Gel: The Influence of Sweet Potato Starch and Konjac Glucomannan

This study investigated the effect of sweet potato starch (SPS) and konjac glucomannan (KGM) on the textural, color, sensory, rheological properties, and microstructures of plant-based pork rinds. Plant-based gels were prepared using mixtures of soy protein isolate (SPI), soy oil, and NaHCO₃ supplemented with different SPS and KGM concentrations. The texture profile analysis (TPA) results indicated that the hardness, cohesiveness, and chewiness of the samples improved significantly after appropriate SPS and KGM addition. The results obtained via a colorimeter showed no significant differences were found in lightness (L*) between the samples and natural pork rinds after adjusting the SPS and KGM concentrations. Furthermore, the rheological results showed that adding SPS and KGM increased both the storage modulus (G’) and loss modulus (G’’), indicating a firmer gel structure. The images obtained via scanning electron microscopy (SEM) showed that the SPS and KGM contributed to the formation of a more compact gel structure. A mathematical model allowed for a more objective sensory evaluation, with the 40% SPS samples and the 0.4% KGM samples being considered the most similar to natural pork rinds, which provided a comparable texture, appearance, and mouthfeel. This study proposed a possible schematic model for the gelling mechanism of plant-based pork rinds: the three-dimensional network structures of the samples may result from the interaction between SPS, SPI, and soybean oil, while the addition of KGM and NaHCO₃ enabled a more stable gel structure.     

液相色谱串联质谱法测定牛肉制品中猪肉含量

建立了超高效液相色谱-串联质谱法测定牛肉制品中猪肉含量的方法.样品经蛋白提取、酶解等前处理后,在0.1％甲酸水和乙腈的梯度洗脱下经C18色谱柱分离,多反应监测模式采集质谱数据进行定量分析,线性回归系数>0.999,方法定量限低至0.5％(w:w),回收率89.6％～109％,相对标准偏差低于10％.     

一种新型固相萃取柱结合超高效液相色谱-串联质谱法选择性富集测定猪肉中的盐酸克伦特罗

发展了一种测定猪肉中盐酸克伦特罗残留的简便、高效、准确的固相萃取-超高效液相色谱-串联质谱(SPE-UPLC-MS/MS)的方法。将搅碎的猪肉样品用5%(v/v)高氯酸超声提取,再以10000 r/min离心15 min后,上清液用SMCX固相萃取柱进行富集和净化。因SMCX是以硅胶为基质兼有反相/强阳离子交换的混合作用模式,因此可以有效地去除复杂基质干扰,达到目标样品的选择性富集和净化的目的。方法学结果表明,该方法在0.25～50 μg/kg范围内具有良好的线性关系,相关系数r为0.9982; 3个添加水平(1.25、12.5、50 μg/kg)的平均回收率为62.2%～ 72.0%,相对标准偏差(RSDs)为4.2%～ 6.1%;检出限(S/N=3)为0.05 μg/kg。所发展的样品前处理和检测方法简单、快速,可用于瘦肉精类成分的选择性富集和分离检测。     

Pork Heart Tissue‐Based Chemiluminescence Biosensor for Pyruvic Acid

Abstract

A novel chemiluminescence (CL) animal tissue‐based sensor for pyruvic acid is presented in this paper. Pork heart tissue was chopped into small pieces and packed into a mini‐glass column as the recognition element. When pyruvic acid passed through the column, hydrogen peroxide was produced under the catalytic oxidation of oxygen by pyruvic acid oxidase present in the pork heart tissue. This produced hydrogen peroxide could react with luminol in alkaline solution to produce chemiluminescence in the presence of potassium hexacyanoferrate(III). The developed sensor system promises simplicity, fastness, stability, and sensitivity. Under the optimum conditions, CL intensities are proportional to the concentration of pyruvic acid in the range of 0.02–12 µmol/L, with a detection limit of 0.004 µmol/L (3σ). RSD is 2.3% for 0.5 µmol/L pyruvic acid (n=11). The sensor could be stable for 150 min by more than 100 times determination. The proposed method has been applied successfully to the analysis of pyruvic acid in biological samples. The results obtained by the proposed method are consistent with those obtained by spectrophotometry.     

Comparison of three solid-phase extraction processes in quantification of ciprofloxacin and enrofloxacin in pork meat

Due to strong implications for food safety, control of fluoroquinolones residues in swine meat should be undertaken to verify compliance of the contamination levels with the maximum residue limits recently updated by Commission Regulation (EU) No. 37/2010 of 22 December 2009. Solid-phase extraction is widely used in antibiotic analysis in food of animal origin. In this study, the results of a comparative study using different types of solid-phase extraction columns, HLB, MCX, and MAX, for ciprofloxacin and enrofloxacin analysis, in pork meat, are presented. In addition, diverse sample treatments for defatting, precipitate proteins, eliminate cations, and increase the ionic strength, were used to obtain the most suitable method of analysis. Only the MCX's use followed by liquid chromatography with fluorescence detection resulted in chromatograms that allow the quantification at maximum residue limits. The validation method, in terms of CCα and CCβ, recovery and precision determination, was according to the EU Decision 2002/657/EC. This procedure was used in the analysis of 50 samples of pork meat of Portuguese origin. Only two samples presented residues of enrofloxacin at 30 and 42 μg/kg, values under the legal maximum residue limit.     

高效液相色谱-串联质谱法测定猪组织中的土拉霉素

建立了高效液相色谱-串联质谱法测定土拉霉素在猪肝脏、肾脏、肌肉、皮脂和肺脏中的残留检测方法,并初步探讨了土拉霉素的基质效应.样品用乙腈提取,涡旋振荡离心后经正己烷脱脂,C18固相萃取柱净化后,40℃氮气吹干,用50%乙腈定容.以Penomenex Luna C18柱为色谱柱,乙腈-2 mmol,/L乙酸铵水溶液(含0....     

同位素稀释液相色谱-串联质谱法准确测定猪肉中的氯霉素

建立了同位素稀释质谱测定猪肉中氯霉素残留的方法,对影响溶剂提取、萃取净化、液相色谱-质谱检测方法准确度的因素进行了量化与优化。猪肉样品经液氮冷冻粉碎,加入氯霉素-D5同位素内标和0.1 mol/L醋酸钠缓冲溶液(pH 5),用乙酸乙酯提取4次,正己烷脱脂,HLB固相萃取小柱净化后采用负离子多反应监测模式下的液相色谱-质谱技术检测。方法的线性范围为0.01～0.5 ng/g,相关系数r2大于0.999;检出限和定量限分别为0.004 ng/g和0.02 ng/g;在0.02 ng/g和1.0 ng/g加标水平的回收率(n=3)分别为95.2%～109.1%和99.7%～102.5%;日内和日间相对标准偏差均小于2%。研究了氯霉素及氯霉素-D5的基体效应,测得不同流动相和稀释溶剂组成时基体效应因子k的范围在0.950～1.015之间。研究结果对同位素稀释质谱痕量残留检测结果准确度的控制、方法的建立与验证具有参考意义。     

UPLC-MS/MS法测定猪肉中万古霉素与去甲万古霉素

建立了快速、准确、灵敏的猪肉中万古霉素和去甲万古霉素的超高效液相色谱串联三重四极杆质谱(UPLC-MS/MS)检测方法。样品经0.1%甲酸-乙腈(7∶3,体积比)提取,正己烷(乙腈饱和)脱脂后,以LC-C18固相萃取小柱净化,采用乙腈-0.1%甲酸为流动相进行梯度洗脱,串联质谱ESI正模式电离,多反应监测(MRM)模式检测,以保留时间和子离子比定性,外标法定量。结果表明,万古霉素和去甲万古霉素可在3 min内分离完全,在1～50μg/L范围内线性关系良好,相关系数均大于0.99,方法检出限(S/N=3)分别为0.5μg/kg和0.3μg/kg;加标水平为1～20μg/kg时(n=6),平均回收率为80%～88%,日内相对标准偏差不高于13.4%,日间相对标准偏差不高于12.5%。方法准确、灵敏,适用于猪肉中万古霉素和去甲万古霉素等糖肽类抗生素的测定。