气相色谱法直接测定动物组织中盐酸克仑特罗的残留量

1　实验部分1.1　仪器与试剂　　ＨＰ6890气相色谱/氮磷检测器,超声波清洗器,离心机,组织匀浆机,吹氮浓缩仪,Ｃ18固相萃取小柱。　　盐酸克仑特罗(又名:瘦肉精)标准储备液(1 0ｇ/Ｌ):称取盐酸克仑特罗标准品(中国药品生物制品检定所)25 0ｍｇ,用0 01ｍｏｌ/Ｌ盐酸定容至25ｍＬ。　　盐酸克仑特罗标准工作液(40.0ｍｇ/Ｌ):取1 0ｍＬ标准储备液,用ＮａＯＨ(2ｍｏｌ/Ｌ)调ｐＨ至12,用5ｍＬ乙酸乙酯提取3次,合并提取液,并用乙酸乙酯定容至25ｍＬ。乙酸乙酯、三氯乙酸、氢氧化钠均为分析纯,盐酸为优级纯。1.2　实验方法　　色谱条件　色谱柱:ＨＰ…     

流动注射化学发光法测定盐酸米诺环素

在碱性条件下,K3[Fe(CN)6]氧化鲁米诺产生化学发光,盐酸米诺环素对该体系化学发光反应具有显著的抑制作用,据此建立了快速测定盐酸米诺环素的流动注射化学发光新方法。在优化的实验条件下,化学发光抑制强度与盐酸米诺环素的质量浓度在8.0~400 ng/m L范围内呈良好的线性关系,检出限为7.4 ng/m L。对200 ng/m L盐酸米诺环素连续平行测定11次,相对标准偏差为1.8%。方法可用于盐酸米诺环素片剂的测定。     

衍生化固相微萃取-色谱质谱法快速检测猪尿中的β-受体兴奋剂

应用固相微萃取法提取猪尿中的盐酸克仑特罗，经顶空衍生后以GC-MS法测定。聚丙烯酸酯纤维对克仑特罗吸附良好，萃取温度、时间、溶液的pH值，以及衍生温度、时间、衍生剂用量等影响因素经过优化。方法线性范围为1-500μg/L，检出限为0.5μg/L。方法快速、灵敏，其相对标准偏差为3.9％-6.8％，标准加入回收率为82.0％-87.7％。     

国内首创瘦肉精检测试剂盒

前不久,国际上第一个用单抗对盐酸克仑特罗(俗称瘦肉精)进行检测的试剂盒在张家港诞生,负责这一项目的张家港出入境检验检疫局与扬州大学畜牧兽医学院盐酸克仑特罗课题联合攻关小组已着手准备该课题的鉴定。 盐酸克仑特罗由于本身促生长和提高胴体瘦肉率的特性,长期以来一直被人们作为促生长添加剂使用,但由于其本身对心血管有毒性,在许多国家相继被禁止使用,我国农业部在1997年就颁布了有关法规禁止在动物饲料中添加克     

荧光光谱法研究克仑特罗与蛋白质的结合作用

应用荧光光谱法研究了水溶液中盐酸克仑特罗与牛血清白蛋白分子间的结合反应 ,测定了结合常数 (K =2 .84× 1 0 3 L mol)和结合位点数 (n =5 .65)。依据F ster非辐射能量转移理论 ,确定了授体 受体间的结合距离 (r=1 .69nm)和能量转移效率 ,采用同步荧光技术考察了盐酸克仑特罗对牛血清白蛋白构象的影响。利用盐酸克仑特罗对蛋白质荧光猝灭 ,对作用机理做了初步探讨     

鲁米诺-铁氰化钾化学发光体系测定盐酸异丙肾上腺素

在碱性条件下，铁氰化钾氧化鲁米诺产生发光，盐酸异丙肾上腺素对该体系有显著的增强作用。基于此并结合流动注射技术建立了测定盐酸异丙肾上腺素的新方法。该方法具有很高的灵敏度，检出限为8．6ng／L(IUPAC)；线性范围为0．05～10μg/L。对1．0μg/L盐酸异丙肾上腺素平行测定11次，其相对标准偏差为3．6％。     

盐酸克仑特罗片剂中克仑特罗及其杂质含量的HPLC测定

建立了测定盐酸克仑特罗片剂含量的高效液相色谱法。选用Agilent Eclipse XDB-C8柱(4.6 mm×250 mm,5μm),流动相为甲醇-水(40∶60,含20 mmol.L-1磷酸二氢钾,以磷酸调至pH 4.0),流速为1.0 mL.min-1,检测波长240 nm,线性范围为0.50~50.0 mg.L-1(r=0.999 9),检出限为0.5 ng,回收率在98.5~102.0%之间,RSD为2.06%~3.07%(n=5)。     

气相色谱法测定盐酸克仑特罗片含量

盐酸克仑特罗(Clenbuteroli Hydrochloridum)是一种平喘药,主要用于防治支气管哮喘和喘息性支气管炎。化学名称是1-(4-氨基-3,5-二氯苯基-2-叔丁氨基乙醇的盐酸盐,其结构式为 其制剂(片)中含量测定卫生部药品标准和山东省药品标准均采用重氮化—偶合比色法。盐酸克仑特罗在酸性(HCl液)介质中加亚硝酸钠重氮化后,再加盐酸萘乙二胺偶合生成偶氮化合物,在500nm波长处测吸收度。由于在重氮化过程中过量亚硝酸可使偶合试剂变色,干扰显色反应,因此需加氨基磺酸胺     

正交实验优化的氢化物发生原子荧光法测定水中痕量锑

采用盐酸为介质,以顺序注射-氢化物发生原子荧光法测定生产用水中的锑含量．通过正交实验确定了仪器工作参数,研究了介质浓度、KBH4浓度、硫脲一抗坏血酸加入量等因素对测定结果的影响,探讨了共存离子的干扰．在选定的最佳实验条件下,方法的检出限为0．011ng/mL,线性范围0～8ng／mL,相对标准偏差为2．78％～6．20％,加标回收率为91．0％～99．1％．该方法操作简便,灵敏度高,准确度好,与微波消解法相比较,两者无显著性差异．     

衍生荧光法测定盐酸西布曲明

通过衍生反应，建立了用荧光光度法测定盐酸西布曲明的新方法。并对衍生体系、反应条件、产物稳定性等进行了研究。实验确定丙二酸和乙酸酐混合试剂与盐酸西布曲明在75℃的水浴中加热15min，所得产物发射强荧光，最大激发波长λcx=456nm，最大发射波长λem=496nm。在上述波长下，荧光强度与盐酸西布曲明的质量浓度在0．11～9．5μg／mL范围内呈良好的线性关系，检出限为13．4ng／mL，标准加入回收率在95．4％～104．2％。用于曲美胶囊中盐酸西布曲明的测定。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.