动物源性食品中磺胺类药物残留的固相萃取-高效液相色谱法测定

研究了动物源性食品中磺胺嘧啶、磺胺二甲嘧啶、磺胺间甲氧嘧啶、磺胺喹啉药物残留的提取、净化和高效液相色谱分析条件 ,建立了高效液相色谱法同时测定动物源性食品中磺胺类药物残留的方法 ,该法检出限为0.010×10-6～0.020×10-6(w) ,添加回收率为71 %～83 %。     

固相萃取-离子色谱法分析胺液中的热稳态盐离子组成

建立了固相萃取(SPE)-离子色谱(IC)法测定脱硫胺液中热稳态盐(HSS)离子的分析方法,优化了萃取上样量、流速、解吸溶剂等条件。Cl-、2－4SO、SCN-、HCOO-、H3CCOO-和H3CH2CCOO-的检出限为0.02×10-6(w),0.1×10-6(w),0.4×10-6(w),0.002×10-6(w),0.15×10-6(w),0.4×10-6(w),相对标准偏差(RSD,n＝6)为3.2%～7.6%。同时建立了离子交换-容量法分析胺液中的热稳态盐分析方法,对离子交换和固相萃取两种处理样品的方法进行了对比,SPE法检出限低而且重复性好。采用SPE-IC和离子交换-容量法,对实际胺液样品进行分析对比,实验结果表明当胺液中HSS的含量大于1%时,采用容量法简单快速;当HSS的含量小于1%时,采用固相微萃取法-离子交换法比较准确。     

茶叶中噻嗪酮残留量的GC-MS测定

采用样品处理的微量化学法和固相萃取技术,建立了茶叶中噻嗪酮残留量的GC -MS测定方法 ;用丙酮 -正己烷 (体积比1∶1)萃取 ,活性碳和中性氧化铝小柱净化 ,净化液用GC -MS测定,外标法定量 ;方法回收率在88%～109 %之间,相对标准偏差为2 %～4 %,测定限为0.010×10-6(w);该法快速、灵敏、准确 ,各项技术指标均满足残留量检测的要求。     

生物材料中克伦特罗的气相色谱-质谱法测定

建立了生物材料中克伦特罗 (clenbuterol)的气相色谱 -质谱测定方法 ;大白鼠喂食克伦特罗获得阳性生物材料 ,生物材料中克伦特罗经0.01mol/L盐酸溶液提取 ,乙醚脱脂净化 ,乙酸乙酯提取后蒸发至干 ,用乙醇溶解后加样到氧化铝柱上 ,用0.01mol/L盐酸溶液洗脱 ,蒸发至干后 ,用BSTFA(双三甲基硅烷基三氟乙酰胺 ) +1 % (φ)TMCS(三甲基氯硅烷 )衍生 ,采用GC -MS进行测定 ,外标法定量 ;试验表明 ,生物材料中添加0.056×10 -6～0.54×10 -6(w)含量水平的克伦特罗 ,方法回收率在89 %～107 % ,相对标准偏差为7.3 %～16 % ,线性相关系数r为0.998,克伦特罗的检出限为2.0×10-9(w)。     

饲料中盐酸克伦特罗、沙丁胺醇高效液相色谱测定

建立了用液相色谱法同时测定饲料中违禁药物盐酸克伦特罗、沙丁胺醇含量的方法 ;样品经甲醇 -盐酸溶液提取后 ,经液 -液萃取、固相萃取小柱净化 ,用ZorbaxCN柱分离 ,二极管阵列检测器检测、外标法定量 ;盐酸克伦特罗、沙丁胺醇的定量下限(w)分别为0.10×10-6 、0.36×10-6,回收率分别大于88 %和74 % ,RSD(n=5)分别小于6.4 %和3.0%。     

FAAS法连续测定电解二氧化锰中微量铜铅钴镍

电解二氧化锰作为电池的正极活性物[1] ,产品多样化 ,可适应不同类型电池和配方的要求 ,其中无汞碱锰电池级电解二氧化锰已成为主导性产品[2 ] 。国内外各大电池厂商对无汞碱锰电池级电解二氧化锰的化学纯度要求为 :≤ 10 0× 10 - 6 级 :w(Fe)一般低于 6 0× 10 - 6 ;≤ 5× 10 - 6 级 :w (Cu、Pb、Co、Ni)一般低于 1× 10 - 6 ;≤ 1× 10 - 6 级 :w(As、Sb、V、Mo)一般低于 1× 10 - 6 。由此可见 ,电解二氧化锰中铜、铅、钴、镍等杂质含量的高低成为评价其产品质量的重要指标。对这些相当低量的杂质元素 ,一般情况下需采用石墨炉原子…     

食品微晶蜡中苯及甲苯残留的顶空气相色谱法测定

应用带有顶空进样器气相色谱仪, 采用外标法定量, 分析食品微晶蜡中苯及甲苯残留量 ; 选择以食品用白油为母液制备一系列标准样品, 在选择的色谱条件下分析, 苯和甲苯含量分别在 10× 10-9～ 2 000× 10-9(w)间与峰面积呈现良好的线性关系, 检出限 (S/N=2)为 5× 10-9(w).     

棉花植株及土壤中丙硫克百威及其代谢物残留气相色谱测定

研究超声波提取、毛细管气相色谱配氮磷检测器(NPD)检测棉花植株及土壤中丙硫克百威及其代谢物残留 ,各组分回收率83%～110 % ,线性范围0.1～100mg/L,最低检测质量分数0.01×10-6～0.02×10-6(w) ;该法具有简单、快速、节省试剂的特点     

用混合粘合剂修饰的碳糊电极测定诺氟沙星

在pH10.50的磷酸盐缓冲溶液中 ,当含有0.8mmol/L的NH4Cl,8mg/L的SLS(十二烷基磺酸钠)时 ,诺氟沙星在由69.1% (w)的石墨粉、24.5 % (w)的液体石蜡和6.4 % (w)的甘油组成的混合粘合剂碳糊电极上产生一灵敏的阴极溶出还原峰 ,峰电位为 -1.61V ;峰电流与诺氟沙星浓度在8.0×10 -9～4.0×10 -7mol/L范围内呈良好的线性关系 ,相关系数为r=0.9949 ,检出限为3.0×10-9 mol/L ;该法用于测定诺氟沙星胶囊含量 ,结果令人满意     

鲁米诺-H2O2Fe(Ⅲ)-Tween-80化学发光与应用

研究了Fe(Ⅲ)催化鲁米诺-H2O2体系化学发光反应.用EDTA作掩蔽剂,非离子表面活性剂吐温-80为敏化剂,Fe(Ⅲ)的最低检出线为6.8×10-8g/L.在Fe(Ⅲ)的浓度范围1×10-6～1×10-4g/L及检测1×10-5g/L Fe(Ⅲ)的浓度时,相对标准偏差(RSD)为2.6%.大多数元素不干扰,回收率为97%～108%.     

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.