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1.
土壤中多种有机氯及拟除虫菊酯类农药的GC-ECD测定   总被引:1,自引:0,他引:1  
气相色谱法同时测定土壤中多种有机氯及拟除虫菊酯类农药。对土壤的分析结果:有机氯农药的检出限0.001~0、003μg/mL,拟除虫菊酯类农药检出限0.008~0.02μg/mL,线性相关系数0.9978~0.9999。用y(石油醚):V(丙酮)=3:1超声波提取,有机氯农药回收率94.2%~124.0%,相对标准偏差为3.3%~8.8%(n=5);拟除虫菊酯类农药回收率95.2%~118.3%,相对标准偏差为5.7%~7.1%(n=5);方法适用于土壤样品中农药残留测定。  相似文献   

2.
在超声波辅助下,以正己烷-二氯甲烷(1:1,V/V)混合溶剂提取样品,提取液用弗罗里硅土和中性氧化铝混合柱净化,用气相色谱-电子捕获检测器(GC-ECD)同时测定茶叶中18种有机氯和9种拟除虫菊酯类农药残留。有机氯农药在0.001-0.2μg/mL,拟除虫菊酯类农药在0.005-1.0μg/mL范围内线性良好。有机氯农药在0.04、0.01μg/mL两个添加水平的回收率分别为89.5%-113.2%和80.0%-112.7%,相对标准偏差分别为3.82%-9.64%和5.32%-13.8%。拟除虫菊酯在0.2、O.05μg/mL两个添加水平的回收率分别为97.5%-129.6%和87.3%-110.2%,相对标准偏差分别为3.78%-10.72%和3.02%-13.84%。本方法快速、灵敏、准确、可靠,用于江西茶叶样品中有机农药残留测定,获得较好结果。  相似文献   

3.
茶叶中多种拟除虫菊酯类农药残留量的气相色谱-质谱测定   总被引:36,自引:0,他引:36  
李拥军  黄志强  戴华  张莹 《分析化学》2002,30(7):865-868
采用微量化学法和固相萃取技术,用丙酮/正己烷(1 1,V/V)萃取,活性炭和中性氧化铝小柱净化,用GC/MS可同时测定茶叶中6种拟除虫菊酯类农药的残留量。方法回收率在84.6%-115.1%之间,相对标准偏差为3%-7%,最低定量检出浓度在0.010-0.20mg/kg之间。该法快速、灵敏、准确,各项技术指标均衡足农残检测的要求。  相似文献   

4.
提出了气相色谱-串联质谱法测定罗非鱼中7种拟除虫菊酯类农药(联苯菊酯、甲氰菊酯、三氟氯氰菊酯、氯菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯)残留量的方法。样品以环己烷-乙酸乙酯(1+1)混合液为萃取剂,经加速溶剂萃取仪提取后,经Florisil固相萃取小柱净化后,用丙酮-正己烷(1+9)混合液淋洗,洗脱液于45℃水浴氮吹近干后用正己烷定容至1 mL,通过TR-5MS毛细管色谱柱分离,采用电子轰击离子源选择反应监测模式进行质谱测定。7种拟除虫菊酯类农药的检出限(3S/N)在0.20~2.1μg·kg-1之间。以空白罗非鱼样品为基体,加入标准溶液进行回收试验,测得回收率在57.9%~107%之间,测定值的相对标准偏差(n=6)均小于12.0%。  相似文献   

5.
焦慧泽  陆世清  侯迪  张前前 《色谱》2019,37(6):605-611
建立了加速溶剂萃取(ASE)-超高效液相色谱(UPLC)-串联质谱法(MS/MS)测定茶叶中拟除虫菊酯类农药残留的方法。ASE萃取温度为80 ℃,萃取压力为10.34 MPa,以正己烷-丙酮(2∶1,v/v)为溶剂静态萃取5 min,循环一次。萃取液浓缩后经GCB/NH2-Florisil柱净化,UPLC分离,MS/MS正离子扫描(ESI+)、多反应离子监测(MRM)模式进行分析,外标法定量。线性回归分析表明:10种拟除虫菊酯的浓度与其峰面积的线性关系显著,相关系数(r)均不小于0.9995,检出限(LOD)在0.5~5.0 μg/kg之间,定量限(LOQ)在1.6~16.6 μg/kg之间;在定量限、0.4 mg/kg以及最高残留限量(MRL,无MRL的加入1 mg/kg)3个水平进行添加回收试验(n=7),回收率为68.7%~103.8%,RSD为0.8%~13.2%。该方法前处理简单,耗时短,灵敏度和准确度高,可满足茶叶中痕量拟除虫菊酯类农药残留测定的要求。  相似文献   

6.
采用气相色谱法测定荔枝中联苯菊酯、甲氰菊酯、氯氟氰菊酯、氟氯氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯等7种拟除虫菊酯类农药的残留量。荔枝样品用丙酮-正己烷(1+1)混合液提取,所得提取液用活性炭柱和中性氧化铝柱的串联柱净化,用DB-35毛细管色谱柱分离,电子捕获检测器检测。7种拟除虫菊酯类农药的质量浓度均在0.05~0.8mg·L~(-1)内与其峰面积呈线性关系,方法的检出限(3S/N)在0.005~0.01mg·kg~(-1)之间。在0.05,0.1,0.2mg·kg~(-1)等3个浓度水平进行加标回收试验和精密度试验,回收率在81.0%~104%之间,测定值的相对标准偏差(n=6)在1.7%~5.1%之间。采用此法测定了荔枝样品中联苯菊酯的含量,所得测定值与行业标准方法测定结果相符。  相似文献   

7.
中药材中5种拟除虫菊酯农药残留量的测定   总被引:9,自引:0,他引:9  
王旗  杨彬  刘庆  李晓婷 《分析试验室》2006,25(12):99-102
研究中药材中5种拟除虫菊酯农药残留量的测定方法。用石油醚-丙酮混合溶剂超声提取,固相萃取法净化,用气相色谱-电子捕获检测器(ECD)测定。5种拟除虫菊酯农药在3种代表性中药材的加标回收率为72.6%-135.0%,相对标准偏差为3.6%。27%;方法的检出限为0.001—0.005μg/g。方法灵敏度高,选择性好,操作较为简便,适用于植物性(根、茎类)药材中5种拟除虫菊酯农药残留量的测定。  相似文献   

8.
建立了蔬菜及其制品中16种有机氯农药和8种拟除虫菊酯类农药残留量的气相色谱分析方法. 样品用V(丙酮)∶V(正己烷)=1∶1提取, 加入20 g/L Na2SO4溶液用正己烷进行液液分配, 提取液用硅镁吸附剂层析柱净化, 采用DB-1701与DB-5毛细管柱分离, 双塔同时进样双GC-uECD同时检测, 双柱定性定量, 在两个水平添加时的回收率(n=6)分别为79.8~118.7%和85.6%~118.8%, 相对标准偏差分别为2.1%~9.2%和1.8%~8.6%, 该方法的检出限为有机氯农药0.001 mg/kg, 联苯菊酯、甲氰菊酯和三氟氯氰菊酯为0.002 mg/kg, 其余5种拟除虫菊酯类农药0.005 mg/kg.  相似文献   

9.
黄微  李娜  徐瑞晗  李婷  李崇勇 《色谱》2018,36(12):1303-1310
建立了加速溶剂萃取(ASE)-固相萃取净化(SPE)-气相色谱-串联质谱(GC-MS/MS)同时测定茶叶中9种拟除虫菊酯类农药残留的方法。ASE萃取溶剂为丙酮-正己烷(1:1,v/v),萃取温度为100℃,萃取压力为10 MPa,加热时间为3 min,静态萃取时间为5 min,循环1次,冲洗体积为40%萃取池体积,氮气吹扫100 s。萃取结束后用Cleanert TPT固相萃取柱净化,净化液浓缩定容后,采用GC-MS/MS测定,外标法定量。9种拟除虫菊酯类农药在2~1000 μg/L范围内呈现良好的线性关系,相关系数(r2)均大于0.99,方法检出限为0.2~4.5 μg/kg,定量限为0.8~15.0 μg/kg。在绿茶、红茶空白基质中做加标回收试验,添加水平为0.02、0.1、0.4 mg/kg以及定量限水平,得到的平均回收率为69.87%~110.0%,相对标准偏差(RSD)为0.7%~11.2%。该方法背景干扰低、灵敏度高、重现性好、回收率稳定,适用于茶叶中拟除虫菊酯类农药残留量的检测。  相似文献   

10.
建立了快速滤过型净化(m-PFC)结合气相色谱-串联质谱(GC-MS/MS)测定茶叶中10种拟除虫菊酯类农药残留的方法。比较了采用不同提取溶剂(乙腈、丙酮和乙酸乙酯)和不同提取方式(不加水浸泡和加水浸泡)时10种农药的提取效率;比较了2种QuEChERS净化管和m-PFC柱对茶叶提取液的净化效果和农药残留的回收率。结果表明,茶叶样品不加水浸泡,用乙腈提取效果最好;m-PFC柱对茶叶提取液净化效果良好,而且能保证较高的农药回收率。10种拟除虫菊酯农药在相应的范围内有良好的线性关系,相关系数(R2)大于0.9980;10种农药在4个水平添加下的回收率为87.5%~111.3%,RSD为2.1%~8.9%。方法的检出限为0.001~0.015 mg/kg,定量限为0.003~0.05 mg/kg。利用该方法检测市售50例茶叶样品中10种拟除虫菊酯农药的残留,检出率为48%,但农药残留量均在国家标准限量值以下。与传统QuEChERS法和固相萃取法相比,该方法具有操作简单、准确度和精密度良好等优点,为多种拟除虫菊酯类农药在茶叶中的残留测定提供了快速检测的新方法。  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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