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131.
132.
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
133.
Gang XU Cheng Cai AN Jun FENG Yun Xiang CI Jin Hua TIAN Zhang Liang CHENI 《中国化学快报》2000,11(7):597-600
IthasbeenreportedthatTrichosanthi11(TCS),isolatedfromrkiI-ilolt)ii,hasanti-tumorI-4andanti-vira1activities5-'.Someanti-tun1orremedies,whicharedesignedfromTCS,arebeingtestedanddeveloped'-.'.StudyingthebioIogicalphenomenonbyelectrochemicalmethodsisanewhotresearchspotemerginginrecentyears".Manyresultsshowedthatnotonlytheenzymesystemsuchassuccinatedehydrogenasedisplayedthediode-likebehaviorduringtheelectrontransferprocess",butalsothehigh1yorganizedorganeIle,forexample,mitochondria,andevenintac… 相似文献
134.
Cs-Fe-Co-Bi-Mn-Mo复合氧化物选择性催化氧化异丁烯 总被引:2,自引:0,他引:2
Mixed oxide catalyst Cs0.1 Fe2Co6BiMnMo12 Ox was prepared by the interprecipitation method, then the catalyst was calcined at different temperature. Selective oxidation of isobutene was carried out in a fixed-bed reactor. The results showed that the catalyst has high catalytic activity. Under the optimum reaction conditions ( n(-C4^= ) : n(O2) = 1:2-1:4, space velocity = 180h^-1, T = 360℃ ), the yield of methacmlein and methacrylic reached 80%, 8 %,respectively. The total yields of liquid products( methacrolein, methacrylic acid and acetic acid) reached about 90%. 相似文献
135.
Chi -ping Lau 《manuscripta mathematica》1987,59(1):53-62
It is shown that if the order of non-uniformity of a quasi-linear elliptic equation is h,1
0,2(h–1)/h norm. For 0h1,existence of a bounded solution is guaranteed without any smallness assumption on the given boundary data.More precise information is given for the special case of the minimal surface equation. 相似文献
136.
Albrecht H Binder U Harder G Lembke-Koppitz I Philipp A Schmidt-Parzefall W Schröder H Schulz HD Wurth R Donker JP Drescher A Matthiesen U Scheck H Spaan B Spengler J Wegener aD Gabriel JC Schubert KR Stiewe J Waldi R Weseler S Brown NN Edwards KW Frisken WR Fukunaga C Gilkinson DJ Gingrich DM Goddard M Kapitza H Kim PC Kutschke R MacFarlane DB McKenna JA McLean KW Nilsson AW Orr RS Padley P Patel PM Prentice JD Seywerd HC Stacey BJ Yoon T Yun JC Ammar R Coppage D Davis R Kanekal S Kwak N 《Physical review letters》1986,56(6):549-552
137.
ZHU Jun ZHANG Yun CHEN Hao CHE Yun-Xia ZHENG Ji-Min ② 《结构化学》2006,25(8):1011-1013
1 INTRODUCTION Nonlinear optics (NLO) is at the forefront of cur- rent researches because of its importance in provi- ding the key functions of frequency shifting, optical modulation, optical switching, optical logic and op- tical memory for the emerging … 相似文献
138.
Treatment of (thd)H (thd=2,2,6,6-tetramethyl-3,5-heptandionate) with excess Os3(CO)12 in an autoclave at 180°C gives the formation of a brown metal chain complex [Os2(CO)5(thd)2]2 (1) and a yellow CO2 cluster complex [Os4(-H)(-CO2)(thd)(CO)13] (2) in low yields. Complex 2 was fully identified by a combination of spectroscopic methods and X-ray diffraction study, showing a unique CO2 ligand bridging a triosmium metal fragment, Os3(-H)(CO)10 and a monometallic osmium fragment, Os(CO)3(thd). Upon treatment of 1 with Me3NO at an elevated temperature, oxidation of the CO ligand occurred at the position trans to the unique CO2 ligand on the Os(CO)3(thd) fragment, giving the formation of a second CO2 cluster [Os4(-H)(-CO2)(thd)(CO)12(NCMe)] (3), which is stabilized by a weakly coordinated acetonitrile molecule. 相似文献
139.
固相萃取-高效液相色谱法测定烟草中的两种多羟基吡嗪异构体 总被引:3,自引:0,他引:3
用固相萃取-高效液相色谱-二极管阵列检测法建立了测定烟草中两种多羟基吡嗪异构体的方法.烟草中的2-(1′,2′,3′,4′-四羟基丁基)-5-(2″,3″,4″-三羟基丁基)-吡嗪(2,5-DOF)和2-(1′,2′,3′,4′-四羟基丁基)-6-(2″,3″,4″-三羟基丁基)-吡嗪(2,6-DOF)用甲醇索氏萃取2h后,提取液用Waters Sep-Park-C18固相萃取小柱预分离,选择Waters carbohydrate analysis(3.9 mm×300 mm)色谱柱(NH2柱),V(乙腈)∶V(水)=80∶20为流动相,流速:1.0 mL/min,烟草中的2,5-DOF及2,6-DOF达到基线分离.两种异构体的标准曲线的线性回归系数均大于0.9996,线性范围为0.5~100 μg/mL;标准回收率分别为98%和104%;相对标准偏差均小于3%;检出限为0.2 μg/mL.用该方法测定了不同卷烟中的2,6-DOF和2,5-DOF两种异构体. 相似文献
140.
Two new compounds from Zingiber officinale 总被引:1,自引:0,他引:1
Yu Zhao Qiao Feng Tao Rong Ping Zhang Chang Xin Zhou Hui Dou Shu Yun Shi Ye Cheng Xiao Lian Li Sun Su Zeng Ke Xin Huang Xiao Dong Zhang Xiao Kun Li 《中国化学快报》2007,18(10):1247-1249
A new cyclic diarylheptanoid,1,5-epoxy-3-hydroxy-1-(3-methoxy-4,5-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane (1),as well as a new monoterpene,10-O-β-D-glucopyranosyl-hydroxy cineole (2) were isolated from the rhizomes of Zingiber officinale. The structures of compounds 1 and 2 were established based on their spectral data.In addition,the antioxidant activities of these compounds were also measured. 相似文献