Solid substrate-room temperature phosphorimetry for the determination of residual clenbuterol hydrochloride based on the catalysis of sodium periodate oxidizing eosine Y

Clenbuterol hydrochloride (CLB) could catalyze NaIO₄ oxidation of eosine Y (R), which caused the room temperature phosphorescence (RTP) signal of R to quench sharply. The ΔI_P (=I_P2 − I_P1, I_P2 was RTP intensities of reagent blank and I_P1 was RTP intensities of test solution) of the system was directly proportional to the content of CLB. According to that academic thought, a new solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace CLB has been established. This method has high sensitivity (detection limit (LD): 0.021 zg spot⁻¹, corresponding concentration: 5.2 × 10⁻²⁰ g mL⁻¹) and good selectivity (Er = ±5%, interfering species were of no interference). It has been applied to the determination of residual CLB in the practical samples. The results were verified using HPLC and GC/MS methods. The reaction mechanism of catalytic SS-RTP for the determination of residual CLB was also discussed.     

固相萃取-气相色谱法测定动物组织中盐酸克伦特罗残留量

建立了固相萃取-气相色谱分析动物组织中盐酸克伦特罗残留量的方法．采用固相萃取,分离富集动物组织中的盐酸克伦特罗．肉样的加标回收率在70％～80％;最低检出限为1μg／kg．盐酸克伦特罗的硅烷化衍生产物,采用气相色谱(ECD检测器)检测,其衍生物的峰面积与样品浓度在0．005～1．0μg／mL范围内呈良好的线性关系,线性回归系数大于0．999．     

克伦特罗残留的GC-MS确证分析及应注意事项

克伦特罗(clenduterol,C12H18Cl2N2O)属β兴奋剂类,俗称为瘦肉精,畜牧业上可作为生长促进剂,其药物残留对人类健康有危害,我国农业部将其列为食品动物禁止使用的兽药。对于动物组织、尿中盐酸克伦特罗残留的测定,一般是先用酶联免疫检测法进行筛选,由于酶联法存在假阳性问题,对检测结果呈阳性的样品需再用气相色谱-质谱法进行确汪检测。本文建立并验证了与酶联免疫检测法相配套使用的猪尿和猪肝中克伦特罗残留的GC-MS确证方法,并对来自全国抽检的猪肝样和尿样中的酶联阳性样品进行了确证检测,结果报道如下。     

Quantification of Clenbuterol in Human Plasma and Urine by Liquid Chromatography-Tandem Mass Spectrometry

The quantitative determination of clenbuterol in human plasma and urine is of particular interest for various fields such as clinical and forensic research and doping controls. A simple and rapid sample preparation procedure based on liquid-liquid extraction with subsequent re-extraction followed by liquid chromatography and electrospray ionization tandem mass spectrometry allowed the determination of clenbuterol in urine and plasma at detection and quantification limits of 0.1 ng mL⁻¹ and 0.2 ng mL⁻¹, respectively, with recoveries ranging from 85–96%. The fast and robust nature of the assay provides a rapid and cost-effective alternative to established procedures utilizing solid-phase extraction strategies.     

β-环糊精衍生物/Cu_2O毛细管电色谱整体柱的制备及其应用

采用一步键合法制备了烯丙胺-β-环糊精/Cu_2O(Ally-β-CD/Cu_2O)毛细管电色谱整体柱,并考察了制备整体柱的主要影响因素。通过扫描电子显微镜(SEM)、X-射线光电子能谱(XPS)、X-射线衍射(XRD)对整体柱柱内固定相进行表征。以硫脲为中性标记物测定了柱效,柱效达到47 658 N/m。对D,L-组氨酸对映体的分离度RS达到3.82,整体柱在连续使用72h或间歇使用2个月后仍具有良好的分离能力,表明整体柱具有良好的重现性和稳定性,同时具备较好的手性拆分能力。运用该整体柱对盐酸克伦特罗对映体进行了拆分,达到基线分离,分离度达到2.89。     

盐酸克伦特罗在纳米ZnO和多壁碳纳米管修饰玻碳电极上的电化学行为

制备了纳米ZnO与多壁碳纳米管(MWNTs)复合修饰玻碳电极(ZnO-MWNTs/GCE),考察了盐酸克伦特罗(CLB)在该修饰电极上的电化学行为。实验结果表明:纳米ZnO与MWNTs显著增强了修饰电极对盐酸克伦特罗的伏安响应,增加了电极的有效表面积,改善了电极的导电性和电催化活性。在2~30μmol·L-1和30~500μmol·L-1浓度范围内,CLB在所制备的修饰电极上的电流响应与其浓度线性关系良好,且该电极具有较好的重现性和稳定性。     

高效毛细管电泳对克伦特罗对映体的分离及定量检测

以羟丙基-β-环糊精(HP-β-CD)作为手性添加剂,采用毛细管区带电泳(CZE)成功分离了克伦特罗(Clenbuterol,Cle)对映体.研究了β-CD种类与浓度,缓冲液pH值及浓度,操作温度等对分离的影响.结果表明,以30 mmol/L的HP-β-CD为手性添加剂,50 mmol/L的磷酸盐缓冲溶液(pH 2.5)为缓中液,分离电压24 kV,操作温度20℃,可使Cle对映体实现基线分离,其分离度为6.78.对拆分机理也进行了探讨,测定了HP-β-CD与两对映体的结合常数及热力学参数;对CZE定量能力(线性,精度)进行了考察,R和S型的线性相关系数都大于0.998,两者的相对标准偏差(RSD)均低于2.2%.     

1 H NMR Spectral Simplification with Achiral and Chiral Lanthanide Shift Reagents. Clenbuterol. Method for Direct Optical Purity Determination

The 60 MHz ¹H NMR spectra of clenbuterol, 1, have been studied in CDCl₃ solution with the achiral shift reagent, tris (6,6,7,7,8,8,8-hepta-fluoro-2,2-dimethyl-3,5-octanedionato)europium (III), 2, and the chiral reagent tris[3-(heptafluoropropylhydroxyn1ethyl-ene)-(+)-canphorato]europiunr(III), 3. Use of 3 resulted in observable enantiomeric shift differences, ΔΔσ, for the t-butyl, NH₂ benzylic CH and the aryl proton signals. Values of ΔΔσ as high as 135.1 Hz (2.25 ppm) and 86.5 Hz (1.44 ppn) were seen for the methine and aryl protons, respectively, with a solution 0.1035 molal in 1 and a 1:3 molar ratio of 0.551. The aryl resonance is especially well suited for direct optical purity determinations of 1.     

固相萃取-高效液相色谱法同时测定克伦特罗和沙丁胺醇

提出用固相萃取 -高效液相色谱法同时测定饲料中微量克伦特罗和沙丁胺醇的新方法。选用 Dikma Diamonsil C18-ODS分析柱 (2 0 0× 4.6mm,5μm) ,乙腈 -0 .0 1mol/ L KH2 PO4 (p H 3 .0 )作流动相 ,应用波长编程进行检测。克伦特罗和沙丁胺醇的线性范围为 0 .1～ 1 0 0μg/ m L,相关系数分别为 0 .99999和 0 .99977,检出限分别为0 .3 1 ng/ m L和 0 .2 4ng/ m L ,回收率分别为 91 .2 %～ 92 .0 %和 91 .9%～ 93 .0 % ,相对标准偏差分别是 1 .2 0 %～ 2 .0 5%和 1 .2 9%～ 2 .51 %。     

Influence of the storage conditions on the concentration of clenbuterol in cattle urine samples

A study of the stability of clenbuterol in cattle urine samples under different time and temperature storing conditions is reported. At the farm, urine samples were spiked with several amounts of this compound. Then, they were immediately transported to the laboratory and stored at room temperature, between 4 and 8 °C and frozen. Clenbuterol was quantified by using high performance liquid chromatography with diode-array detection (HPLC-PDA) on days 1, 7 and 42 after sample collection. The drug concentration in frozen urine samples was apparently stable during the whole studied period. However, there was a notable decrease in the concentration of this analyte when samples were stored at room temperature and between 4 and 8 °C, specially during the first week. A complementary study showed that the decrease in clenbuterol concentration was particularly significant from 1st to 4th day after sample collection and when urine specimens were kept at room temperature. Based on the results of this study, it was concluded that sample freezing as soon as possible after collection is the most adequate way to guarantee that the reliable concentration of clenbuterol in urine specimens remains unchanging until sample analysis.