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1.
用2-琉基苯并噻唑/醋酸丁酯pH7~8萃取体系,预浓集以后,用火焰原子吸收测定环境水中癌量Cu,Zn,Cd、Pb,回收率在95%~105%,相对标准偏差为2%~5%(x=6),植出限为Cu0.2μg/L,Zn0.08μg/L、Cd0.03μg/L、Pb0.8μg/L。  相似文献   

2.
生物样品中Se的荧光测定方法   总被引:1,自引:0,他引:1  
运用微波消化系统处理生物样品,以2,3-二氨基萘为荧光试剂建立了一种测定生物样品中Se的荧光分光光度法。方法的最低检出限为1.6ng/mL,线性范围0~0.600μg/mL,回收率92.22%~99.78%,连续10次测定样品变异系数(CV)为0.4%(n=10),隔213重复实验变异系数为1.54%。该法具有灵敏、稳定、可靠等优点,适用于生物样品中Se含量的测定。  相似文献   

3.
古汉养生精中微量元素的ICP-MS分析   总被引:3,自引:0,他引:3  
本文报道用ICP—MS法同时测定样品中Pb、As、Cu、Zn、Cd、Cr、Ni、Mn等8种微量元素。样品用微波消解。对影响测定的各种因素进行了研究,实验确定了最佳测定条件。本法的检出限为0.01~0.08μg/L,回收率为92.11%~112.82%,RSD小于4.30%。方法准确、快速、简便,应用于古汉养生精中微量元素的测定,结果满意。  相似文献   

4.
采用NHO3+HF+H2O2体系微波消解垃圾焚烧飞灰,火焰原子吸收光谱法测定金属Cu,Fe,Pb,Ni,Mn,Cr和Cd的含量。结果表明,飞灰中Cu质量分数为0.8927mg/g,Pb质量分数为1.8490mg/g,Ni质量分数为0.1523mg/g,Mn质量分数为1.1033mg/g,Fe质量分数为86.4517mg/g,Cr质量分数为0.3667mg/g,Cd质量分数为0.0581mg/g。铁的检测限为3.9041mg/L,其它元素均小于1mg/L,加标回收率在98.0%-108.0%之间。RSD〈4.0%。该法简便快速,具有较好的准确度和精密度,测定结果为处理垃圾焚烧所产生的飞灰提供了理论依据。  相似文献   

5.
建立了过氧化钠熔融分解样品、电感耦合等离子发射光谱法(ICP-AES)测定锡精矿中锡、铜、铅、铁的新方法。对试样分解方法、过氧化钠用量、元素分析谱线等进行了讨论。选择过氧化钠用量为2.0g,样品熔融温度为850~C,锡、铜、铅、铁分析谱线分别为189.991,324.754,220.353,259.940nm。将该方法应用于标准样品(BY0107—1)中Sn,Cu,Pb,Fe的测定,待测元素的回收率在92.0%-101.6%之间,检出限为分别为0.006,0.002,0.005,0.001μg/mL,测定结果的相对标准偏差为0.16%~2.11%(n=5)。  相似文献   

6.
微波消解-GFAAS测定浅水湖泊底泥中重金属元素   总被引:1,自引:0,他引:1  
探讨了采用微波消解作为底泥样品的前处理方法,运用石墨炉原子吸收法测定浅水湖泊底泥中Cu,Pb,Zn,Cd,Cr含量的实验条件.方法的RSD为2.0%~4.1%,平均回收率为97.4%~101.5%,Cu,Pb,Zn,Cd,Cr的检出限分别为0.4,5,2.8,0.25,2.5ng.该法适合于浅水湖泊底泥中重金属含量的测定.  相似文献   

7.
建立了用弗罗里硅土作基质固相分散剂的加速溶剂萃取、并以灭蚁灵(Mirex)为内标的快速、同时测定土壤中16种有机氯农药的气相色谱法。加速溶剂萃取仪在100℃,10.3Mpa用正己烷和丙酮(1:1,V/V)静态提取样品10min,0.01μg/g加标水平回收率为77.3%-101.3%;方法检出限为0.01—0.04ng/g。方法满足了土壤中有机氯农药残留测定的要求。对我国南方不同地域的72个土壤样品进行了测定,大部分有机氯农药在土壤中都有一定检出量,其中环氧七氯最高(2.6~844.5ng/g),甲氧DDT(23.2—219.8ng/g)和P,P’-DDT(4.0—183.1ng/g)次之,而o,P'-DDT在72个土样中都没有检出。  相似文献   

8.
微波辅助萃取气相色谱-质谱联用测定蔬菜中的扑草净   总被引:4,自引:0,他引:4  
研究了微波辅助萃取气相色谱.质谱联用测定植物样品中扑草净的方法,比较了几种不同溶剂的微波萃取效率,从而选取二氯甲烷为萃取溶剂,并采用三因素三水平的正交设计试验对溶剂体积、微波辐射时间、微波功率进行了优化。在优化的实验条件下分析了合成菠菜样品,对0.2μg/g和0.02μg/g的合成菠菜样品,回收率分别为99.5%和92.5%,相对标准偏差分别为5.0%和ll%,方法的线性范围为1.0—400ng/g,检出限为0.22ng/g。方法适合于分析植物样品中的扑草净。  相似文献   

9.
王爱霞  郭黎平  张宏 《分析化学》2005,33(3):385-388
采用双柱富集的流动注射在线预富集系统与220FS顺序多元素原子吸收分光光度计联用,使用圆锥型活性炭微柱为预富集柱,在pH4~5.5范围内,以吡咯啶二硫代氨基甲酸铵(APDC)为络合剂,6mol/L HNO3为洗脱剂,实现了Cu、Co、Ni、Cd、Pb5种元素的快速顺序测定。该体系对以上5种元素的富集倍数为9.8~15.5之间,34s富集的检出限(3σ)Cu为1.81,Co为3.10,Ni为1.66,Cd为0.28,Pb为4.90μg/L;相对标准偏差Cu 1.13%;Co1.24%;Ni2.26%;Cd0.95%;Pb1.77%。  相似文献   

10.
建立了同时测定牡蛎中16种有机氯农药残留量的前处理方法和气相色谱分析方法。在100℃的温度条件下,用加速溶剂提取(ASE)提取样品中的有机氯农药,用凝胶渗透色谱(GPC)结合Florisil柱净化,以RTX-5MS毛细管色谱柱分离、ECD检测器测定。结果表明,样品的加标回收率(n=3)为81%~110%,方法检出限为0.2~0.7ng/g,样品检测的相对标准偏差为2.9%~15.2%。  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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