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1.
固相微萃取-气相色谱法分析水中痕量1-萘酚   总被引:4,自引:1,他引:3  
利用固相微萃取(SPME)-气相色谱法(GC)分析了水中前量的1-萘酚。对于SPME萃取头,溶液介质条件、吸附和解吸时间进行了研究。结果表明,PA_85萃取头对于水中1-萘酚的富集效果最佳。而无机盐氯化钠的加入和降低PH值可以明显地改善萃取效果。在优化后的条件下,SPME-GC方法对于水中1-萘酚的检测限可达0.5μg/L,分析过程中标准偏差均小于4%。  相似文献   

2.
提出了用β-二酮类试剂1-苯基-3-甲基-4苯甲酰基-吡唑酮[5](PMBP)为萃取剂和 化学改进剂的电热蒸发电感耦合等离子体原子发射光谱(ETV—ICP—AES)测定高纯ZrO2 中痕量Eu的新方法。讨论了影响Eu-PMBP 螯合物蒸发的主要因素。在优化实验条件下,Eu 的检出限为0.9μg/L,相对标准偏差为3.4%,试样分析的回收率为94.5%~105.2%.  相似文献   

3.
锑(锡)—Ferron—Se(Ⅳ)络合吸附催化波研究及应用   总被引:1,自引:1,他引:1  
在pH1.8的H2SO4-NaAc缓冲溶液中,用单扫示波极谱法,Sb(Ⅲ)或者(Sn(Ⅳ)-7-碘-8-羟基喹啉-5-磺酸-Se(Ⅳ)体系可产生灵敏的络合吸附催化波。锑、锡浓度分别在0.4~200μg/L和0.8~180μg/L范围内与峰高呈线性关系,检测限分别为0.2μg/L和0.4μg/L,并用于工业废水,地下水和天然水中痕量锑和锡的测定,同时对电话性络合物的组成,极谱波的性质和电极过程机理也  相似文献   

4.
在pH1.8的H_2SO_4-NaAc缓冲溶液中,用单扫示波极谱法,Sb(Ⅲ)或者Sn(Ⅳ)-7-碘-8-羟基喹啉-5-磺酸-Se(Ⅳ)体系可产生灵敏的络合吸附催化波。锑、锡浓度分别在0.4~200μg/L和0.8~180μg/L范围内与峰高呈线性关系,检测限分别为0.2μg/L和0.4μg/L,并用于工业废水、地下水和天然水中痕量锑和锡的测定。同时对电活性络合物的组成、极谱波的性质和电极过程机理也作了讨论和研究。  相似文献   

5.
潘海祥  麦碧娴 《分析化学》1999,27(2):140-144
参照美国EPA525.1方法,C18-固相萃取膜萃取饮用水中的有机物,利用GC/MS法鉴定多环芳烃(PAHS),使用16种多环芳烃混合标准样绘制标准曲线,以内标法对PAHS进行定量分析。采用本方法某水厂经过深度处理后的出厂水中的7种多环芳烃的含量,PAHS的平均回收率为94.0-97.7%。检测限为0.001μg/L。  相似文献   

6.
气相色谱/质谱法测定大鼠脑中5-羟色胺的含量   总被引:4,自引:1,他引:3  
梁天天  黄亦佳  朱卡琳 《色谱》1998,16(3):271-273
采用气相色谱/质谱法(GC/MS)测定了正常大鼠和服药大鼠脑组织中5-羟色胺(5-HT)的浓度。大鼠脑组织制成匀浆后,先将5-HT酰化,酰化物经乙酸乙酯提取后,再经七氟丁酸酐衍生化,用GC/MS测定。MS采用电子捕获负离子化学电离(ECNICI)模式。方法的线性范围为0.50~50.0μg/L,回归方程为Y=0.1348X-0.07995(r=0.9996);平均回收率为98.2%±3.8%(n=10);检测限为0.5μg/L;相对标准偏差小于10%。  相似文献   

7.
丁基罗丹明B—钼酸盐光度法连续测定铈和钪   总被引:4,自引:0,他引:4  
王加林  徐其亨 《分析化学》1996,24(3):344-347
在聚乙烯醇(PVA)存在下,丁基罗丹明B(BRB)分别与铈钼、钪钼杂多酸络阴离子形成离子缔合物,其最大吸收均位于570nm,表面摩尔吸光度分别为εCe=3.96×10^6L.mol^-1.cm^-1,εSc=4.71×10^5L.mol^-1.cm^-1,服从比耳定律范围分别为0-24μg/L Ce和0-60μg/LSc,测定极限为Ce1.0μg/L(n=12)和Sc1.9μg/L(n=10),对  相似文献   

8.
固相微萃取与色谱联用方法分析水中12种有机氯化合物   总被引:18,自引:0,他引:18  
运用顶空固相微萃取与色谱闻用方法(HS-SPME-GC)对水中的残留有机氯化合物进行了分析。对影响HS-SPME-GC分析灵敏度的各种实验因素如涂层种类,萃取温度、平衡时间,离子浓度等进行了讨论并将该方法与固相萃取法(SPE),液液萃取法(LLE)作了对比,同时考察了常见环境共存污染物直链烷基苯磺酸钠(LAS)对几种方法的影响。  相似文献   

9.
聚乙烯醇对锌镉铅溶出增敏作用及应用   总被引:3,自引:0,他引:3  
张文德  李彦  郭忠 《分析化学》1999,27(11):1289-1291
在0.05mol/L(pH6.5)乙二妥-盐酸介质中,聚乙烯醇-124PVA-124)对锌,镉,铅的电位溶出有显著的增敏作用。当富集60s时,其检出限均达6.0μg/L,线性范围:锌0.6-35μg/L,镉0.6-45μg/L,铅0.6-50μg/L。标准加入回收率为92.4%-110%。RSD(n-4)〈7.0%。  相似文献   

10.
倒数示波计时电位法同时测定粮食中Cu、Pb含量   总被引:1,自引:0,他引:1  
在分别含有2g/L乙二胺与*10^-4mol/L8-羟基喹啉(Oxine)和0.3mol/L的氢氧化钠淀粉液中,Cu^2+、Pb^2+具有良好的示波图。其切口电位分别为-0.85V,-120V(vs.SCE),二者相差0.35V,能够分辨,可同时测定,本方法应用于大米中Cu、Pb含量的同时测定,检出限分别为5.8μg/L(Cu)、10.0μg/L(Pb),平均回收率为96.0%、102.0%。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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%).  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
19.
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 CuI 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).  相似文献   

20.
(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.  相似文献   

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