同位素稀释-气相色谱三重四极杆质谱法测定水性内墙涂料中的苯酚与氯代苯酚防霉杀菌剂

建立了同位素稀释-气相色谱串联三重四极杆质谱(GC-MS/MS)测定水性内墙涂料中苯酚及氯代苯酚(2-氯苯酚、2,4-二氯苯酚、2,4,6-三氯苯酚、2,3,4,6-四氯苯酚、五氯苯酚、邻苯基苯酚和六氯芬)防霉杀菌剂的方法。样品加入同位素内标,经甲醇超声提取,乙酸酐衍生后正己烷提取,采用GC-MS/MS测定,内标法定量,方法检出限均为0.005 mg/kg。目标物在0.02~1 mg/kg范围内线性良好,相关系数大于0.99,添加回收率为75.3%~107.6%,相对标准偏差为4.3%~14%。方法可以满足以丙烯酸、聚醋酸乙烯-丙烯酸和聚苯乙烯-丙烯酸为基材的水性内墙涂料中氯酚类防霉杀菌剂残留的检测要求。     

液相色谱串联质谱法同时测定鳗鱼中阿维菌素和伊维菌素残留量

使用高效液相色谱/串联质谱仪(LC/MS/MS)同时测定鳗鱼肌肉中的阿维菌素(AVM)和伊维菌素(IVM)残留量:采用乙酸乙酯提取均质后的鳗鱼样品,提取液过碱性氧化铝柱净化去脂,采用(LC/MS/MS)电喷雾电离(ESI)源,正离子多反应检测(MRM)模式检测,外标法定量。测定结果表明:阿维菌素检出限为1.0 ng/g,在添加浓度0~20 ng/g之间,呈线性相关,相关系数为0.9997,对于1、2、4 ng/g添加水平回收率范围81.5%~103.0%,相对标准偏差(RSDs)范围4.53%~7.09%;伊维菌素检出限为2.0 ng/g,在添加浓度0~20 ng/g之间,呈线性相关,相关系数为0.9990,对于2、4、8 ng/g添加水平回收率范围83.5%~94.8%,相对标准偏差(RSD)范围3.57%~6.06%。     

气相色谱-质谱法测定水产品中19种氯代酚及其钠盐

建立了用气相色谱-质谱(GC-MS)联用法测定水产品中19种氯代酚及其钠盐的分析方法。试样用H_2SO_4消解后,用环己烷-乙酸乙酯提取酸解液中的氯代酚,利用酚类易溶于稀碱溶液的性质,将氯代酚提取到稀碱液中,调稀碱液pH至微酸性,用二氯甲烷-正己烷溶液萃取,无水Na_2SO_4脱水,浓缩定容并硅烷化衍生后,用GC-MS仪EI源选择离子模式检测,氘代4-氯-3-甲基酚(PCMC-d_2)和氘代2,4,6-三溴苯酚(2,4,6-TBP-d_2)为内标,内标法定量。氯代酚在2.0~70.0μg/L范围内,其浓度和峰面积呈良好的线性相关(r≥0.999);水产品中添加量为1.00μg/kg、2.00μg/kg、3.00μg/kg和7.00μg/kg时,回收率一氯酚(MCP)为55.2%~88.8%,二氯酚(DCP)为63.0%~114%,三氯酚(TCP)为76.0%~116%、四氯酚(TeCP)为78%~125%,五氯酚(PCP)为83.2%~104%;方法检出限在0.2~0.4μg/kg之间。     

微波萃取气相色谱法测定淀粉中14种有机氯农药残留

建立了淀粉中14种有机氯农药:六六六及滴滴涕的4种异构体、五氯硝基苯、四氯硝基苯、四氯苯胺、五氯苯胺、腐霉利、甲基五氯苯基硫醚(MPCPS)的微波辅助和气相色谱分析方法.优化了气相色谱检测条件,考察了提取方法、萃取条件、净化条件对提取效果的影响.目标农药在20～200 μg/kg范围内线性良好,平均回收率在68%～10...     

衍生化-气相色谱-三重四极杆质谱法同时测定粮食作物中三氯甲基吡啶及其代谢物残留

建立了粮食作物中三氯甲基吡啶及其代谢物6-氯吡啶甲酸的衍生化-气相色谱-三重四极杆质谱（GC-MS/MS）检测方法。选取高粱、小麦、玉米及爆谷等典型的粮食作物,采用酸性乙腈提取,以浓硫酸作为三氯甲基吡啶代谢物的衍生化试剂,优化了衍生化反应的最佳反应条件,并使用GC-MS/MS分析,以内标法对三氯甲基吡啶及其代谢物进行定量检测。结果表明,在0.025~0.4 mg/L范围内,线性关系良好,相关系数（r²）均大于0.995,在3个不同添加水平下的平均回收率在80.4%~98.4%之间,相对标准偏差（RSD）在1.0%~10.1%之间。该方法操作简单、高效,灵敏度高,抗干扰能力强,回收率和重复性良好,能够满足粮食作物中三氯甲基吡啶及其代谢产物残留量的检测要求。     

水蒸气蒸馏-活性炭柱固相萃取/GC-MS/MS法测定火腿中8种N-亚硝胺

建立了水蒸气蒸馏提取,活性炭柱固相萃取,气相色谱-串联质谱(GCM S/M S)检测火腿中8种N-亚硝胺的新方法。样品经水蒸气蒸馏提取,馏出液经Sep-Pak AC-2活性炭柱固相萃取进行净化与富集,二氯甲烷洗脱,以多重反应监测(MRM)方式进行GC-MS/MS检测。在考察的浓度范围内(1~400 ng/m L)方法线性良好,R20.9995,除N-二甲基亚硝胺(NDM A)和N-亚硝基甲乙胺(NMEA)检出限≤0.1 ng/g外,其它分析物的检出限为≤0.04 ng/g;在0.3,3和10μg/kg 3个水平的添加回收率为78.7%~118.2%,除N-亚硝基吗啉(NM OR)回收率略低,为45.2%~58.2%,相对标准偏差为2.5%~21%。应用该方法对市售的4种火腿进行检测,结果表明NDMA和N-亚硝基吡咯烷(NPYR)是主要的挥发性N-亚硝胺,含量分别为0.30 ng/g和0.56~0.99 ng/g,N-二乙基亚硝胺(NDEA)、NMOR和N-二丁基亚硝胺(NDBA)均有检出,但含量低于定量限,NM EA、N-二丙基亚硝胺(NDPA)和N-亚硝基哌啶(NPIP)未检出。     

气相色谱-串联质谱法检测化妆品中25种防腐剂

建立了气相色谱-串联质谱（GC-MS/MS）同时测定化妆品中苯甲酸及其酯类、对羟基苯甲酸酯类、苯氧异丙醇、氯苯甘醚、脱氢乙酸、2，6-二叔丁基-4-甲基苯酚、甲基氯异噻唑啉酮和甲基异噻唑啉酮等25种防腐剂的方法。化妆品样品经含0.1 mg/mL L（+）-抗坏血酸甲醇溶液超声提取，以2-辛醇、苯酚、七氯为内标，加入无水硫酸钠脱水，离心过滤后，用GC-MS/MS分析，内标法定量。方法的检出限为0.08~0.99 μg/kg。实验选取了水、乳液、膏霜型3种类型的化妆品基质，在4个加标水平下验证方法的准确度，25种防腐剂的加标回收率为82.3%~119.4%，RSD为0.2~14.3%（n=6）。该方法定性、定量准确，可有效用于化妆品中25种防腐剂的检测。     

稳定同位素稀释液质串联法测定抗菌纺织品中3种含氯防霉抗菌

建立了抗菌纺织品中三氯生、三氯卡班以及五氯酚等3种含氯抗菌剂的同位素稀释-液相色谱串联质谱的分析方法。样品用甲醇超声提取,聚酰胺粉净化。以水/乙腈为流动相,采用梯度洗脱,在Waters Acquity UPLC BEH C18色谱柱(2.1 mm×100 mm,1.7μm)上进行分离,以多反应监测负离子模式进行检测,内标法定量。三氯生和五氯酚在0.5~100.0μg/L,三氯卡班在0.1~50.0μg/L范围内具有良好的线性,样品的回收率为80.0%~110.0%,相对标准偏差(RSD)为1.6%~5.4%,方法的定量限为0.1~0.5μg/kg,检出限为0.03~0.16μg/kg。方法前处理简单,试剂可用于纺织品中三氯生、三氯卡班和五氯酚的含量检测。     

气相色谱-三重四极杆串联质谱法同时测定调味品中的氨基甲酸乙酯和氯丙醇

建立了气相色谱-三重四极杆串联质谱(GC-MS/MS)同时测定调味品中氨基甲酸乙酯(EC)和氯丙醇(3-氯-1,2-丙二醇(3-MCPD)和2-氯-1,3-丙二醇(2-MCPD))的方法。样品添加同位素内标后,采用Extrelut^TM NT有机硅藻土填料进行基质固相分散萃取,先用正己烷淋洗除杂,再用乙酸乙酯-乙醚(20:80, v/v)混合溶剂洗脱被测物,洗脱液经浓缩后采用GC-MS/MS多反应监测(MRM)模式测定。EC、3-MCPD和2-MCPD的方法检出限依次为2、5和5 μg/kg,线性范围依次为5~1000 μg/kg(r=0.9997)、10~1000 μg/kg(r=0.9991)和10~1000 μg/kg(r=0.9995)。酱油、料酒(黄酒)、沙拉酱和方便面调味料4种基体中在20、100和400 μg/kg 3个水平加标测定的平均回收率和相对标准偏差(RSD,n=7)范围分别为EC: 87.7%~104%(RSD为4.3%~10.7%)、3-MCPD: 90.1%~109%(RSD为2.6%~10.2%)、2-MCPD: 90.9%~103%(RSD为3.0%~9.5%)。在部分酱油、料酒和方便面调味料中同时检测到了EC、3-MCPD和2-MCPD,在部分沙拉酱中检测到了EC或3-MCPD。该法准确、快速,适用于调味品中EC、3-MCPD和2-MCPD的同时检测。     

HPLC-MS/MS测定氯羟吡啶在牛奶中的残留

建立了牛奶中氯羟吡啶残留检测的高效液相色谱-串联质谱方法(HPLC-MS/MS)。样品经乙腈提取,碱性氧化铝固相萃取柱(Alumina-B)净化,以乙腈+0.1%甲酸水溶液作为流动相洗脱,采用电喷雾离子源(ESI),多反应监测(MRM)方式进行采集,外标法定量。结果表明,氯羟吡啶在1~200ng·m L-1浓度范围内呈现良好的线性关系,相关系数R2大于0.99,方法检测限为0.2μg·kg-1,从5、10和50μg·kg-13个水平添加浓度检测结果可以看出,方法回收率在93.4%~102.6%,相对标准偏差不大于6.5%。     

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.