CdTe/ZnSe核壳量子点免疫层析试纸条检测克伦特罗的研究

采用巯基丁二酸作为表面修饰剂,水相法合成水溶性的CdTe/ZnSe核壳量子点,然后在N-羟基琥珀酰亚胺(NHS)的作用下,将CdTe/ZnSe核壳量子点与抗克伦特罗多克隆抗体(Anti-CLE pAb)连接。通过凝胶电泳和斑点杂交实验,验证CdTe/ZnSe核壳量子点与Anti-CLE pAb连接成功,并且CdTe/ZnSe-Anti-CLE pAb偶联物能识别克伦特罗-BSA抗原(CLE-BSA)。光谱分析表明,量子点与抗体连接后荧光增强,荧光峰位从628nm红移至635nm。将合成的CdTe/ZnSe-Anti-CLE pAb偶联物作为指示克伦特罗(CLE)分子的荧光标记物,制备出一种用于检测CLE的免疫层析试纸条,其最低检测量可达1μg/L。与ELISA法的对比实验表明,此试纸条能应用于CLE残留的快速检测。     

盐酸克伦特罗在乙炔黑电极上的电化学行为及其分析测定研究

研究了盐酸克伦特罗(CLB)在乙炔黑电极上的电化学行为,发现阴离子表面活性剂十二烷基苯磺酸钠(SDBS)能显著提高CLB的氧化峰电流并降低其氧化过电位。优化了实验参数,建立了一种直接测定CLB的新电分析方法,其线性范围为1.0×10-7~7.5×10-5mol/L,开路富集1 min后的检出限为2.5×10-8mol/L。平行10次测定1.0×10-5mol/L盐酸克伦特的RSD为3.1%。方法用于猪尿中盐酸克伦特罗含量的测定。     

Automated headspace solid‐phase microextraction and on‐fiber derivatization for the determination of clenbuterol in meat products by gas chromatography coupled to mass spectrometry

A method was developed for the determination of clenbuterol in meat using stable‐isotope‐dilution gas chromatography with mass spectrometry coupled with solid‐phase microextraction and on‐fiber derivatization. The samples were first homogenized with hydrochloric acid followed by protein deposition. After headspace solid‐phase microextraction and on‐fiber derivatization, the content of clenbuterol was measured with the aid of stable‐isotope dilution. The condition of solid‐phase microextraction was optimized by central composite design. The relative standard deviations, limit of detection, and recoveries for clenbuterol were 4.2–9.2%, 0.48 μg/kg, and 96–104%, respectively. The proposed method was satisfactory for analysis of real samples as compared with the Chinese standard method.     

A novel immunochromatographic assay based on a time-resolved chemiluminescence strategy for the multiplexed detection of ractopamine and clenbuterol

A novel multiplexed immunochromatographic assay (ICA) based on a time-resolved chemiluminescence (CL) strategy was developed for quantitative detection of β-agonists, by utilizing ractopamine (RAC) and clenbuterol (CLE) as the models. Different from conventional multiplexed ICA methods which usually require two or more test lines, this strategy was developed for detection of two β-agonists by using only one test line on the nitrocellulose membrane. In this study, horseradish peroxidase and alkaline phosphatase were used as the signal probes to label RAC antibody and CLE antibody, respectively. The two CL reactions with flash type and glow type kinetics characteristics were triggered simultaneously by injecting the coreactants, then the signals for RAC and CLE detections were recorded at 3 s and 300 s after coreactants injection, respectively. Owing to the utilization of CL detection, this protocol showed ideal sensitivity for quantitation. Under the optimal conditions, the detection limits for RAC and CLE were 0.17 ng mL⁻¹ and 0.067 ng mL⁻¹ (S/N = 3), respectively. The whole assay process can be accomplished within 20 min without complicated sample pretreatment. The proposed method was successfully applied for the detection of RAC and CLE in spiked swine urine. It opens up a new pathway for designing a low cost, time-efficiency and multiplexed strategy for rapid screening and field assay.     

测定克喘素的离子选择性电极

通过对克喘素－四苯硼酸根和克喘素－硅钨酸根为膜的电活性物、电活性物膜的浓度、增塑剂以及增塑剂与ＰＶＣ组分比等对克素－ＰＶＣ膜电极影响研究,研制嗫克喘素－四苯硼酸活性物,以邻苯二甲酸二壬酯霁了喘素－ＰＶＣ膜离子选择性电极。电极在克喘素浓度为１×１０＾－１￣８×１０＾－６ｍｏｌ／Ｌ范围呈Ｎｅｒｎｓｔ响应平均响应５５ｍＶ／ｐｃ,检测下限３×１０＾－６ｍｏｌ／Ｌ,用于药物片剂克喘素含量测定。     

高效液相色谱法测定肉类中克伦特罗等激素类生长促进剂残留量

肉类样品用乙醇提取,经C18固相萃取柱,甲醇(10+90)2mL淋洗,甲醇2mL洗脱。采用HypersilC18色谱柱(250mm×4.6mm,5μm),甲醇-磷酸(1+99)为流动相(75∶25),流速1mL.min-1,柱温26℃,紫外检测波长240nm测定。克伦特罗、多巴胺、己烯雌酚、睾丸素、黄体酮五种激素类生长促进剂成分可同时测定,检出限分别为0.4,2.4,0.3,0.5,0.4μg.g-1,平均回收率分别为99.0%,98.0%,100.7%,97.5%,94.0%,RSD分别为2.7%,1.2%,2.3%,2.3%,3.5%。检测方法简便快速、可靠准确。     

Preparation,characterization and application of a new 25,27‐bis‐[2‐(5‐methylthiadiazole)thioethoxyl]‐26,28‐dihydroxy‐para‐tert‐butyl calix[4]arene stationary phase for HPLC

A new para‐tert‐butylcalix[4]arene column containing thiadiazole functional groups was prepared and used for the separation of polycyclic aromatic hydrocarbons, phenolic compounds, aromatic amines, benzoic acid and its derivatives by high‐performance liquid chromatography (HPLC). The effect of organic modifier content in the mobile phase on retention and selectivity of these compounds were investigated. The results indicate that the stationary phase behaves like reversed‐phase packing. However, hydrogen bonding, π–π and inclusion interactions seem to be involved in the separation process. The column has been successfully employed for the analysis of clenbuterol in pork and pig casing; the limit of detection and the limit of quantitation for this method by HPLC‐UV detection was 0.03 and 0.097 μg/mL, respectively; the method is demonstrated to be suitable and a competitive alternative analytical method for the determination of clenbuterol.     

Electrochemical Detection of Clenbuterol in Pig Liver at Pyrrole-DNA Modified Boron-doped Diamond Electrode

Introduction Clenbuterol { 4-amino-[( tert-butylamino) meth-yl]-3,5-dichlorobenzyl alcohol hydrochloride} is aβ-agonist drug[1]. It can improve the ratio of muscle tofat when it is administrated with high doses to ani-mals[2,3]. However, the residues of clenbuterol(CL)are toxic to humans, leading to sickness and possibleheart complication[4]. It has been reported that CL iseasy to accumulate in animal livers.Recently, some analytical methods for the detec-tion of CL, such as HPLC[5], GC…     

Screening of Clenbuterol Hydrochloride Aptamers Based on Capillary Electrophoresis

Capillary electrophoresis based systematic evolution of ligands via exponential enrichment (CE-SELEX) was reported as a homogeneous efficient method for high-affinity selection of aptamer, with several merits involving screening in free solution without nonspecific binding, capable of high-efficient separation, low-sample consumption, and saving money. There are few studies regarding the aptamer selection against small molecule using CE-SELEX, resulting from the aspects of less binding sites and the negligible variety of its complex with nucleic acid in the electrophoretic mobility. In this study, we performed the aptamer selection towards a small molecule target of clenbuterol hydrochloride (Clen) by CE-SELEX. In brief, Clen were first incubated with an 80 nt ssDNA library, and CZE-UV approach was used to separate complex and random ssDNA. The complex was then collected into a vial followed by PCR amplification. Through three round selections, the third library was selected to clone and ten sequences were finally obtained. The dissociation constant (K_d) of three potential candidates (Apt 4, Apt 7 and Apt 12) were determined by CE-LIF, and showed high affinities of 9.315 × 10^?7 M, 1.040 × 10^?6 M and 1.143 × 10^?5 M, respectively. The result of m-Fold software analysis showed that the above three sequences could form stem-loop structure, and the Apt 4 gave the lowest free energy and the most stable structure. Using salbutamol as a control, three selected aptamers were verified with high specificity.     

电子束辐照下克伦特罗的降解研究

克伦特罗是一种β2受体兴奋剂，是被欧美和我国农业部严格禁止的兽药。克伦特罗水溶液在电子束辐照下将发生降解。辐照计量不同，克伦特罗降解程度不同。采用质谱法测定克伦特罗溶液辐照前后的变化。当辐照计量大于6kGy时，克伦特罗降解率可达95％以上，说明这种辐照降解法具有一定的应用前景。