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991.
Determination of Organophosphorus Pesticides in Soil by MMSPD-GC-NPD and Confirmation by GC-MS 总被引:1,自引:0,他引:1
A novel method, modified matrix solid-phase dispersion (MMSPD), has been developed for quantitative analysis of organophosphorus
pesticide residues in soil. It was based on matrix solid-phase dispersion (MSPD) and continuous liquid-solid extraction (continuous
LSE), using Florisil as sorbent and dichloromethane as the recycling solvent. Two soils with different texture and physicochemical
properties were studied to validate the method. The effect of residence time of pesticides in soil was also studied. MMSPD
was compared with MSPD and continuous LSE respectively. Determination was carried out by gas chromatography with nitrogen-phosphorus
detection (GC-NPD). The method gave recoveries ranging from 72–105% with relative standard deviations (RSDs) lower than 15%
for the pesticides studied. The limits of detection (LODs) ranged from 0.1 to 0.6 ng g−1. Two pesticide residues have been detected in real soil samples from Fujian, China, using MMSPD. The pesticides were confirmed
by gas chromatography-mass spectrometry (GC-MS) in a selected-ion monitoring (SIM) mode.
Revised: 4 and 9 April 2006 相似文献
992.
JunZhou Yong-zhiQiu Xiao-pengZang Chang-wangPan QiangChen JianShen Si-congLin 《高分子科学》2005,(1):93-102
N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility. 相似文献
993.
合成了六种轻希土硫氰酸盐与标题不饱和冠醚的新固体配合物,进行了元素分析,摩尔电导率、DTA、UV、IR和XPS等表征.对Ln(NCS)3·L和Ln(NCS)3的XPS研究中,得到它们组成原子芯能级电子(Ln3d5/2,Ols,Nls,S2p)的结合能信息;观察到除Y3d5/2外Ln3d5/2(Ln=La、Ce、Pr、Nd、和Sm)的伴峰结构,Ln3d5/2结合能与原子序数呈线性关系,并推断类似化合物Pm3d5/2结合能在1035eV附近. 相似文献
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997.
合成了r,r’-联吡啶为桥的异双核配合物[(H_2O)Cu(dien)(μ-r,r’-bpy)Rh(NH_3)_5](ClO_4)_5·H_2O.研究了单晶结构和ESR谱.晶体属正交晶系,空间群Pbca,晶胞参数:a=14.425(1),b=29.589(2),c=16.893(6)A,Z=8.偏离因子R=0.065.分子中Cu~(2+)和Rh~(3+)分别取五配位的四方锥和六配位的八面体构型,联吡啶桥的2个吡啶面夹角为51°.依据ESR谱计算了3配合物中Cu~(2+)的键参数并讨论了Cu~(2+)的成键性质. 相似文献
998.
Ningyi Chen Jiayi Xu Michael Reuman Xun Li Ronald K. Russell Zhihua Sui 《Tetrahedron letters》2006,47(33):5909-5913
Various substituents were introduced onto the methyl group in 4-methyl coumarins through lithiation, followed by reactions with a wide range of electrophiles. The presence of an alkoxy group on 6′-phenyl ring was found to be pivotal for the success of this reaction. This procedure provided a convenient synthetic pathway to elaborate the methyl group of 4-methylcoumarins. Application of this methodology was showcased with the synthesis of biologically important novel tetracyclic chromene ring systems (n = 1-3). 相似文献
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