超高压液相色谱-串联质谱法测定畜禽粪便中3种β-受体激动剂残留

建立了畜禽粪便中3种β-受体激动剂药物残留的超高压液相色谱-串联四极杆质谱联用仪测定方法。样品酶解后经高氯酸溶液净化,调节p H值至碱性,乙酸乙酯提取,净化浓缩后以流动相定容,用超高压液相色谱-质谱联用仪检测,内标法定量。3种β-受体激动剂在0.5~20.0μg/L范围内线性关系良好,相关系数均大于0.998。畜禽粪便中3种β-受体激动剂的加标回收率为80.3%~110.2%,相对标准偏差为3.0%~7.7%,检出限(S/N=3)为0.04~0.07μg/kg。     

超高效液相色谱-串联质谱法测定畜禽毛发中8种β-受体激动剂

采用超高效液相色谱串联质谱(UPLC-MS/MS)法,通过优化β-受体激动剂在毛发中的提取、净化等前处理过程,建立了一种测定畜禽毛发中8种β-受体激动剂含量的方法。样品经β-葡萄糖醛苷酶/芳基硫酸酯酶酶解,2%甲酸-乙腈溶液提取,MCX固相萃取小柱净化,通过C18色谱柱分离,电喷雾串联质谱多反应监测模式测定。结果表明,8种β-受体激动剂在0.2～10μg/L范围内线性关系良好,相关系数均大于0.991,回收率在71.5%～114.3%之间,相对标准偏差为1.2%～13%。沙丁氨醇、特布他林、氯丙钠林、莱克多巴胺、拖布特罗和喷布特罗的检出限为0.5μg/kg,西马特罗和克伦特罗的检出限为1.0μg/kg。该方法适用于畜禽毛发中8种β-受体激动剂的定性定量分析。     

超高效液相色谱-串联质谱法同时测定牛肉和牛肝中5种β2-受体激动剂

建立了牛肉和牛肝中克仑特罗(clenbuterol)、莱克多巴胺(ractompamine)、沙丁胺醇(salbutamol)、西马特罗(cimaterol)和特布他林(terbutaline)的超高效液相色谱-串联质谱同时快速检测方法。样品经酶解,固相萃取技术（SPE）净化,多反应监测模式（MRM）下进行定性和定量分析。标准工作溶液在0.2~10μg/kg浓度范围内,5种受体激动剂线性关系良好,相关系数R2^{均大于0.99。方法的检出限为0.2μg/kg,定量限为0.5μg/kg。在0.5、1、2μg/kg的添加浓度下,回收率在78.2%~114.2%之间,相对标准偏差在2.0~16.0%之间。方法具有快速、经济、准确等特点,适合于牛肉和牛肝中β2-受体激动剂的快速定量、定性检测。}     

超高效液相色谱-串联质谱测定动物肌肉组织中32种β-激动剂、β-阻滞剂和糖肽类抗生素药物残留

建立了同时测定动物肌肉组织中27种β-激动剂、3种β-阻滞剂和2种糖肽类抗生素的超高效液相色谱-串联质谱(UPLC-MS/MS)方法.样品经酶解、蛋白沉淀后,以乙酸乙酯-异丙醇(6∶4,V/V)提取,Starata-X-C固相萃取净化,BEH C18色谱柱分离,乙腈-0.1％甲酸梯度洗脱,串联质谱ESI+电离,多反应监测模式检测,外标法定量.结果表明,32种目标物在线性范围内相关性良好(R2 ＞0.995),多巴胺、瑞普特罗、万古霉素和去甲万古霉素的方法检出限为5 μg/kg,其它目标物的检出限为3μg/ks;平均加标回收率为83.6％ ～103％,相对标准偏差(n=6)为3.9％ ～ 10.4％,日间精密度为4.5％ ～9.8％.结果表明,本方法准确、灵敏,适用于动物肌肉组织中β-激动剂、β-阻滞剂,以及糖肽类抗生素的高通量测定.     

高效液相色谱-线性离子阱质谱法测定畜禽肌肉中β2-受体激动剂及β-阻断剂类药物残留

利用高效液相色谱-线性离子阱质谱（HPLC-ITMS）以同位素稀释技术测定了肌肉组织中23种β2-受体激动剂及5种β-阻断剂．肌肉样品经5％的三氯乙酸溶液酸解提取,以弱阳离子固相萃取柱进行净化．以甲醇和含0．1％甲酸的水溶液为流动相在液相色谱柱上梯度洗脱分离,采用ESI源正离子模式在选择离子监测（SRM）模式下进行扫描．以9种经氘代同位素标记的β2-受体激动剂为内标进行定量．猪肉中23种β2-受体激动剂及5种β-阻断剂的线性范围为5-200μg／L,相关系数（力大于0．995,各化合物在肌肉中的检出限均能达到0．2gg／kg．以空白猪肉样品进行的加标水平为5、10、20μg／kg的加标回收试验,各化合物的回收率在47．3％-123．7％之间,相对标准偏差在3．2％～25．7％之间．对猪肉样品和鸡肉样品进行了测定,得到了满意的结果．该方法灵敏度高,定性准确,可以用于畜禽肌肉中β2-受体激动剂和β-阻断剂类药物残留的确证检测．     

高效液相色谱-串联质谱测定猪肉中3种β-受体激动剂残留量

建立一种同时测定猪肉中3种β-受体激动剂残留量的高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)确证分析方法。样品经β-葡萄糖醛酸酶/芳基硫酸酯酶酶解、乙酸铵缓冲液提取和MCX固相萃取柱净化,采用Agilent ZorbaxSB-C18(2.1mm×150mm,3.5μm)色谱柱,0.1%的甲酸水溶液、甲醇和乙腈作为流动相进行洗脱,高效液相色谱分离,电喷雾离子源电离,正离子多反应监测模式进行检测,内标法定量。3种药物在0.05～1μg/kg浓度范围内线性良好,相关系数r均大于0.999,0.05、0.1、0.5μg/kg3个浓度水平的添加回收率在89.7%～106.7%之间,相对标准偏差为2.4%～8.6%,3种药物的定量限均为0.05μg/kg。方法适用于猪肉中β-受体激动剂残留的确证分析。     

基质固相分散/高效液相色谱-串联质谱法分析肉肠中4种β-2-受体激动剂残留

利用同位素稀释技术,建立了肉肠中4种β2-受体激动剂克伦特罗、莱克多巴胺、沙丁胺醇和特布他林的基质固相分散/高效液相色谱-串联质谱(MSPD/HPLC-MS/MS)分析方法。样品经C18填料研磨,甲醇洗脱,提取物经酶解后,用MCX小柱净化,经高效液相色谱分离,在正离子多反应监测(MRM)模式下用电喷雾电离串联质谱测定,内标法定量。4种β2-受体激动剂在0.2～20.0μg/L质量浓度范围内呈良好的线性关系,相关系数(r2)均大于0.990;沙丁胺醇和克伦特罗的检出限为0.10μg/kg;莱克多巴胺和特布他林的检出限为0.15μg/kg;方法的回收率为80%～109%,相对标准偏差小于10%。该方法简便快捷、灵敏度高,样品和溶剂用量少,可满足肉肠中4种β2-受体激动剂残留的快速检测。     

UPLC–MS/MS测定动物源食品中9种β-受体激动剂

建立超高效液相色谱–串联质谱法检测动物源食品中克伦特罗、莱克多巴胺、沙丁胺醇、特布他林、氯丙那林、西马特罗、菲诺特罗、妥布特罗、喷布特罗等9种β-受体激动剂的方法。样品经β-葡萄糖醛苷酶酶解,用0.2mol/L乙酸铵溶液(pH 5.2)提取,阳离子固相萃取柱净化,以乙腈–0.2%甲酸水溶液作为流动相进行洗脱,用Eclipse Plus C_(18)(50 mm×2.1 mm,1.8μm)色谱柱分离,采用多反应监测(MRM)模式进行定性和定量分析。9种β-受体激动剂的质量浓度在0.1~10.0 ng/mL范围内与定量离子丰度呈良好的线性关系,线性相关系数均大于0.999,检出限为0.1μg/kg。平均回收率为85.0%~101.2%,测定结果的相对标准偏差为2.8%~9.5%(n=6)。该方法精密度好,灵敏度高,能简便、快速、准确地测定动物源食品中的9种β-受体激动剂。     

高效液相色谱-线性离子阱质谱法测定畜禽肌肉中β_2-受体激动剂及β-阻断剂类药物残留

利用高效液相色谱-线性离子阱质谱(HPLC-ITMS)以同位素稀释技术测定了肌肉组织中23种β2-受体激动剂及5种β-阻断剂.肌肉样品经5%的三氯乙酸溶液酸解提取,以弱阳离子固相萃取柱进行净化.以甲醇和含0.1%甲酸的水溶液为流动相在液相色谱柱上梯度洗脱分离,采用ESI源正离子模式在选择离子监测(SRM)模式下进行扫描.以9种经氘代同位素标记的β2-受体激动剂为内标进行定量.猪肉中23种β2-受体激动剂及5种β-阻断剂的线性范围为5～200μg/L,相关系数(r)大于0.995,各化合物在肌肉中的检出限均能达到0.2μg/kg.以空白猪肉样品进行的加标水平为5、10、20μg/kg的加标回收试验,各化合物的回收率在47.3%～123.7%之间,相对标准偏差在3.2%～25.7%之间.对猪肉样品和鸡肉样品进行了测定,得到了满意的结果.该方法灵敏度高,定性准确,可以用于畜禽肌肉中β2-受体激动剂和β-阻断剂类药物残留的确证检测.     

反相液相色谱-串联质谱法检测猪肝中26种β2-受体激动剂类药物残留

建立了一种猪肝中26种β2-受体激动剂药物残留的反相液相色谱-串联质谱(HPLC-MS/MS)检测方法。样品经β-葡萄糖苷酸酶/芳基硫酸酯酶酶解12 h后,加入HClO4调至pH 1,去除蛋白,残渣经过0.1 mol/L HClO4再次提取后,合并提取液,调节混合提取液至pH 4,过混合阳离子(MCX)固相萃取柱净化。采用0.1%甲酸(A)和0.1%甲酸-乙腈(B)作为流动相进行梯度洗脱,质谱(ESI+)采用多离子检测模式(MRM)对β2-受体激动剂的定量离子和定性离子进行监测,本方法在15 min内完成26种目标化合物的分离分析。26种β2-受体激动剂在5、10和20μg/L添加水平的回收率为64.0%~112.7%,相对标准偏差小于15.2%,方法检出限为0.15~1.35μg/kg。     

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.     

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.