毛细管电泳法测定猪体组织中甜中甜菜碱含量

建立了毛细管电泳法快速测定猪体组织中甜菜碱含量的方法。甜菜碱首先转化为苯甲酰甲基酯后直接上样测定。pH为3.0的磷酸缓冲溶液使甜菜碱酯化物和甜菜碱结构类似物酯化物之间以及酯化物和酯化剂之间都能很好地分离,这也省去了反应混合液的前处理。该法标准曲线的线性范围为4-600mg/L,相关系数r为0.9999,最低检测限为1mg/L,相对标准偏差为2.2%-4.7%,标准加入回收率为95.9%-98.4%。     

抗坏血酸紫外褪色分光光度法测水中余氯

建立了抗坏血酸紫外褪色分光光度法测定水中余氯的新方法. 在pH 2～6介质中, 选择248 nm作为测定波长, 氯质量浓度在0～4.0 mg/L范围服从比尔定律. 回归方程为： ρ=10.109A＋0.0005 （mg/L）, 检出限0.02 mg/L, 水中常见的离子不干扰测定. 该法用于自来水、游泳池水等样品中余氯浓度的测定, 快速简便, 加标回收率在98%～104%之间.     

UPLC-MS/MS法同时检测葡萄和土壤中2种甲氧基丙烯酸酯类杀菌剂残留

采用改进的QuEChERS方法,结合UPLC-MS/MS,建立了葡萄和土壤中同时测定嘧菌酯和吡唑醚菌酯残留快速分析方法。葡萄样品采用乙腈提取,无水MgSO4+乙二胺-N-丙基硅烷+C_(18)固相分散剂净化,土壤样品采用乙腈提取,无水MgSO_4+C_(18)固相分散剂净化,UPLC BEH C_(18)色谱柱分离,三重四极杆电喷雾质谱检测。在质量浓度0. 01～5. 0 mg/L范围内,葡萄和土壤基质中两种杀菌剂的浓度与峰面积之间具有良好的相关性,相关系数均大于0. 99;在葡萄和土壤中添加0. 1～5. 0 mg/kg的嘧菌酯与吡唑醚菌酯,回收率为88. 1%～109. 2%,相对标准偏差为1. 4%～6. 4%。该方法适用于葡萄中和土壤中同时快速检测嘧菌酯和吡唑醚菌酯残留。     

离子色谱法同时测定果汁中20种有机胺、生物胺和阳离子

建立了梯度淋洗-电导抑制-离子色谱法测定果汁中20种有机胺、生物胺和阳离子的方法,通过对流速、色谱柱温度、p H等因素的考察,探索出了适合20种组分测定的多级梯度淋洗条件。结果表明,当流速为0. 25 mL/min,pH在3. 5～4. 5,柱温在40℃时,20种组分在0. 05～2. 00 mg/L浓度范围内具有良好的线性关系(R 0. 99)。20种组分检出限(S/N=3)在0. 0006～0. 0503 mg/L之间;在0. 10,0. 20,1. 00 mg/L 3个添加浓度水平下,回收率为78. 4%～108. 9%,相对标准偏差(RSDs)在2. 1%～7. 3%之间。该方法适用于果汁中20种有机胺、生物胺和阳离子的分析测定。     

气动雾化进样-微波等离子体炬原子发射光谱法测定催化剂中铜和钠

研究了用微波等离子体炬原子发射光谱法(MPT-AES)测定催化剂中铜和钠含量的方法. 考察了测定铜和钠的实验参数, 选择了测定的最佳条件, 并考察了共存离子的干扰情况. 催化剂使用压力溶弹处理, 并用标准加入法来消除基体干扰. 实验结果表明, 铜和钠的检出限分别为2.0、 4.2 μg/L, 方法的RSD均小于2.2%, 线性范围分别为0.01～12.0 mg/L和0.02～8.0 mg/L. 样品测定的RSD均小于2.9%, 加标回收率均在96.1%～102%之间.     

固相萃取-反相高效液相色谱法测定水中的邻苯二甲酸酯

建立了固相萃取-反相高效液相色谱法检测水中3种邻苯二甲酸酯类物质邻苯二甲酸二甲酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二正辛酯的方法. 考察了固相萃取柱、洗脱溶剂、洗脱体积、上样速度以及洗脱速度对萃取效率的影响. 通过综合分析, 选定SupelcleanLC-18 SPE Tube固相萃取柱, 甲醇为洗脱剂, 洗脱体积2 mL, 上样速度为4 mL/min, 洗脱速度为1 mL/min. 在此萃取条件下, 萃取回收率在83.4%～121.2%之间. 邻苯二甲酸二甲酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二正辛酯质量浓度在2～100 mg/L之间均为线性. 经萃取后, 方法的最低检出限分别为邻苯二甲酸二甲酯0.06 μg/L, 邻苯二甲酸二(2-乙基己基)酯0.16 μg/L, 邻苯二甲酸二正辛酯0.08 μg/L. 方法的精密度在10%～15%之间. 应用该方法测定自来水中酞酸酯类化合物的含量, 加标回收率为83.6%～110.2%.     

气相色谱法分离和测定环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯

用活性炭吸附环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯 ,经二硫化碳 (CS2 )解吸后用气相色谱法测定 .在填充 2 .5 %DNP + 2 .5 %Bentone 34/ChromosorbWHPDMCS的玻璃色谱柱 (长 2m内径 3mm)上 ,丙烯酸乙酯与甲基丙烯酸甲酯及干扰物之间能较好地分离 .方法的回收率 :丙烯酸乙酯为 86.4%～ 1 0 3.0 % ,甲基丙烯酸甲酯为 86.3 %～ 1 0 1 .2 % ,变异系数 :丙烯酸乙酯为 4.1 %～ 4.4% ,甲基丙烯酸甲酯为 4.4%～ 4.9% ,当采样体积为 2 0L ,解吸液体积为 2 .0 0mL ,进样 2 μL时 ,丙烯酸乙酯和甲基丙烯酸甲酯的最低检测浓度分别为 0 .0 2mg/m3和 0 .0 1mg/m3.     

协同催化-溶剂萃取光度法测定血清中的唾液酸

利用Cu2+和Cr3+的协同催化作用,促进间苯二酚与唾液酸的显色,再用乙酸丁酯-正丁醇萃取有色物质,变换波长至625nm处测定血清中的唾液酸含量.建立了血清中唾液酸测定的新方法.方法的线性范围为0～1000mg/L,检出限为2.1 mg/L,相对标准偏差为1.59%～2.11%,回收率为96.2%～101.2%,糖类及抗坏血酸等物质对测定的干扰＜2%.该法简便、快速、灵敏、准确,可用于临床体液中唾液酸的测定.     

非水溶剂中微量溶解氧的测定

利用分子氧对联吡啶钌的荧光有淬灭作用的特点,建立了一种灵敏的测定非水体系中微量溶解氧的方法.以甲基三甲氧基硅烷(MTMS)和四乙氧基硅烷(TEOS)为共聚前驱体,以联吡啶钌为荧光指示剂制备了新的有机改性溶胶-凝胶氧敏感膜,并将该膜用于有机体系中溶解氧的测定,响应时间小于30 s.对1,3-丁二醇,丙二醇,丙三醇,PEG-400中溶解氧的测定线性范围分别为0～73.6 mg/L,0～116.4 mg/L,0～205.7 mg/L,0～165.0 mg/L;RSD(n=6)分别为3.5%.5.4%,2.8%和1.0%.该法可用于有机溶剂中溶解氧的测定.     

萃淋树脂分离-全差示光度法测定环境水样中铬Ⅲ和铬Ⅵ

用CL TBP萃淋树脂分离富集Cr 和Cr 、对氨基二甲基苯胺做显色剂 ,采用全差示光度法测定环境水样中的Cr 和Cr 。方法的表观摩尔吸收系数为 3.42× 10 5L·mol- 1 ·cm- 1 ,线性范围为 0～ 0 .16mg/L ,线性方程为A =6 .7C +0 .0 0 1,(C :mg L) ,r =0 .9996 ,Cr 和Cr 的检测限分别为 8和 6 μg L。测定Cr 和Cr 分别为 18.7和 31.6 μg L ,其相对标准偏差分别为 3.1%(n =6 )和 2 .4%(n =6 )。Cr 和Cr 的标准加入回收率为 93.3%～ 10 2 .3%。用本法测定环境水样中Cr 和Cr ,结果满意。     

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.