甘蓝中3种拟除虫菊酯类杀虫剂残留分析方法

建立了甘蓝样品中氯菊酯、胺菊酯、联苯菊酯3种拟除虫菊酯类杀虫剂的多残留气相色谱检测方法.甘蓝样品经乙腈提取,弗罗里硅土柱净化,丙酮-正己烷(体积比1∶9)洗脱,气相色谱-电子捕获检测器测定,外标法定量.结果表明:3种拟除虫菊酯杀虫剂在甘蓝中的添加回收率为83.13%～107.85%(RSD:4.21%～8.33%).     

多壁碳纳米管滤过型净化-气相色谱串联质谱法测定香蕉中5种拟除虫菊酯类杀虫剂残留

[目的]建立了多壁碳纳米管滤过型净化,气相色谱串联质谱技术同时测定香蕉中联苯菊酯等5种拟除虫菊酯类杀虫剂残留量的分析方法。[方法]香蕉样品用乙酸乙酯提取,经多壁碳纳米管滤过型净化柱净化后,用气相色谱-串联质谱法测定。[结果]联苯菊酯等5种拟除虫菊酯类杀虫剂的质量浓度在0.01～0.2 mg/L范围内线性良好,定量限均为10μg/kg,相关系数均大于0.99,平均加标回收率为71.3%～108.3%,相对标准偏差为0.7%～3.6%。[结论]方法学考察及实际样品的测定证明该方法简便、快速、准确,可用于香蕉中联苯菊酯等5种拟除虫菊酯类杀虫剂残留量的检测。     

固相萃取气相色谱法检测烟叶中拟除虫菊酯类杀虫剂残留

[目的]建立烟叶中拟除虫菊酯类杀虫剂多残留的固相萃取-气相色谱检测方法.[方法]烟叶样品经正己烷-乙酸乙酯超声提取、Florisil固相萃取柱净化后,用气相色谱电子捕获检测器检测.[结果]7种拟除虫菊酯类杀虫剂在0.1、0.5、1.0 mg/kg三个加标水平上的回收率为85.32％～101.21％,相对标准偏差为2.97％～4.88％,检出限为0.003～0.005 mg/kg.[结论]该方法灵敏准确,适用于烟叶中拟除虫菊酯类杀虫剂多残留分析.     

毛细管气相色谱法测定中药材中拟除虫菊酯类农药的残留量

建立了中药材中6种拟除虫菊酯类农药残留量测定的气相色谱分析方法。对提取溶剂进行优化,样品以石油醚-丙酮(V/V,2:1)超声提取15min,氟罗里硅土层析柱净化,采用HP-5毛细管柱分离,用GC-ECD同时检测。低、中、高3种浓度(n=3)的加标平均回收率均在80%～120%范围内,符合要求;日内和日间的精密度分别在0.03%～5.50%﹑2.38%～11.43%之间。该方法操作简便、试剂用量少、回收率高、重现性好、分析准确快速,适用于中药材中拟除虫菊酯类农药的残留分析。     

气相色谱-双柱双检测器测定水稻土中菊酯农药的残留

建立全自动索氏提取-气相色谱法双柱双检测器测定水稻土中的7种拟除虫菊酯的分析方法。水稻土经石油醚和丙酮(2∶1)提取后,弗罗里矽小柱净化,ECD检测器分析,外标法定量,对水稻土前处理和仪器条件进行优化。结果表明:石油醚和丙酮(2∶1)提取液的效果及弗罗里矽小柱净化作用较为突出,结果符合农药残留分析要求。7种拟除虫菊酯类农药含量在0.02～0.50mg/L间呈良好的线性关系,相关系数R2均大于0.995。检出限(S/N=3)为0.001～0.003 mg/kg,添加0.02～0.50 mg/kg浓度,平均回收率72.8%～88.6%之间,相对标准偏差(RSD)2.3%～6.7%之间。该方法具有操作简单、灵敏度高、重现性好等特点,适用于水稻土中拟除虫菊酯类农药残留的检测分析。     

菜地土壤中3种拟除虫菊酯类农药的多残留分析

[目的]准确评价拟除虫菊酯类农药在菜地使用后的生态环境安全性。[方法]借助气相色谱分析技术,研究并建立了3种拟除虫菊酯类农药(联苯菊酯、氯氰菊酯、氰戊菊酯)在菜地土壤中的定量分析方法。样品中的拟除虫菊酯类农药用丙酮提取,经石油醚萃取后,用气相色谱仪检测。[结果]当添加质量分数为0.05、0.10、0.50 mg/kg时,方法的最小检出量为5×10-11g,添加回收率为92.24%～108.77%,相对标准偏差为0.36%～6.42%。[结论]方法符合农药残留量分析与检测的技术要求。     

GC–μECD测定浓缩苹果汁中6种拟除虫菊酯类农药残留量

采用GC–μECD法同时测定了浓缩苹果汁中6种拟除虫菊酯类农药残留量。采用固相萃取技术对样品进行净化,用微电子捕获检测器、SPB–5毛细管气相色谱柱,对浓缩苹果汁中6种拟除虫菊酯同时进行测定,可取得满意的结果。该方法的检测限为0.0054mg/L～0.0460mg/L,样品平均加标回收率为99.8%～104.0%。     

固相萃取-气相色谱质谱法测定水中4种拟除虫菊酯类农药

采用固相萃取-气相色谱质谱法测定水中4种拟除虫菊酯类农药(丙烯菊酯、联苯菊酯、甲氰菊酯和溴氰菊酯).实验选取C18固相萃取柱,二氯甲烷∶乙酸乙酯(1∶1)作为萃取溶剂,萃取液经后N2吹至近干,用1mL丙酮定容后进行分析.该方法操作步骤简单,检出限低,加标回收率和精密度满足分析测试要求,适用于水中拟除虫菊酯类农药残留的分析.     

气相色谱法快速测定叶类蔬菜中拟除虫菊酯类农药残留

建立了快速测定叶类蔬菜中拟除虫菊酯残留量的气相色谱方法。叶类蔬菜中的拟除虫菊酯经丙酮-石油醚混合液超声波辅助提取,经中性氧化铝-石墨化碳柱净化,正己烷定容,用外标法定量,以气相色谱法（GC-μECD）测定。试验结果表明：样品以0.20、0.10、0.05 mg/kg水平添加时,联苯菊酯、三氟氯氰菊酯、顺式氰戊菊酯和溴氰菊酯回收率分别为78.5%～104.3%,80.5%～106.5%,85.3%～107%,84.5%～108.5%,最低检出限为0.001 mg/L,相对标准偏差小于5%。     

QuEChERS-气相色谱法同时测定蜂花粉中多种有机氯和拟除虫菊酯残留量

建立了QuEChERS-气相色谱法同时测定蜂花粉中9种有机氯类和6种拟除虫菊酯类农药残留的定性定量分析方法。蜂花粉样品用乙酸乙酯-正己烷混合溶液提取,QuEChERS技术净化,气相色谱-电子捕获检测器分析,外标法定量。结果表明:该法能有效分离9种有机氯和6种拟除虫菊酯农药,峰形良好,且在10~200μg/L浓度范围内线性良好,检出限0.05~0.30μg/kg,相关系数R均大于0.997,75.1%~103.5%,RSD为1.9%~7.9%。该方法简单、快速、高效,适用于有机氯类和拟除虫菊酯类农药残留限量的检测要求。     

薰衣草油提取和切割方法的研究

以正己烷、丙酮为溶剂,分别采用溶剂萃取法和水蒸气蒸馏提取薰衣草油,通过GC/MS定性分析提取物组成。结果表明,溶剂萃取法的收率是水蒸气蒸馏的 5倍以上,且萃取物中乙酸芳樟酯含量高于后者,峰面积百分比达到 20%以上,但杂峰数量多;相对来说,丙酮提取物中的低沸点组分偏多,正己烷提取物中的高沸点组分偏多。水蒸气蒸馏提取物中芳樟醇的峰面积百分比达到 34%,樟脑的峰面积百分比超过 5%,均明显高于溶剂萃取。针对正辛烷 /正庚烷 /异戊醇模拟体系的水蒸气蒸馏实验表明,水蒸气蒸馏能优先提取混合物中低沸点、强极性组分,可用于薰衣草油的精制和切割。     

Determination and Correlation of Solubility of Nonivamide in Different Solvents☆

The solubility of nonivamide in dimethyl sulfoxide, methanol, acetone, ethyl acetate, methyl tert-butyl ether, ace-tonitrile, n-hexane and water over the temperature range of 293.2 K to 323.2 K was mea...     

童亭煤族组分的溶剂萃取及萃取物分析

采用正己烷、甲醇、丙酮和氯仿4种溶剂对童亭煤经CS2/NMP混合溶剂萃取和反萃取所分离的3个族组分(沥青质组分、精煤和萃余煤组分)进行索氏分级分次萃取,以FTIR和GC为分析测试手段,研究各组分萃取物的结构特征和其中小分子的赋存规律。结果表明:各族组分在不同溶剂中溶解能力差异显著,沥青质组分在正己烷中有很高的萃取率,而精煤则在丙酮中有大量物质被溶出,萃余煤在氯仿中表现出较高的可溶性;各族组分可溶物在溶出行为和组成结构上既有相似性又存在一定的差别;各族组分可溶物中均有小分子化合物存在,且这些GC可检测的小分子主要集中于一定的保留时间区域内;不同族组分中的小分子的赋存形态具有相似性,且这种赋存形态是影响小分子溶出行为的决定性因素。     

反气相色谱法研究增塑剂-探针分子的热力学性能

利用凝胶色谱(GPC)、热重分析(TGA)、表面张力仪和差示扫描量热(DSC)法等对增塑剂环烷油的分子结构及其基本性能进行了表征。以不同种类的溶剂作为探针分子,采用反气相色谱(IGC)法对增塑剂的热力学性能进行了研究。结果表明:在试验温度(50～80℃)范围内,正戊烷、正己烷、正庚烷、环己烷、氯仿、苯和乙醚是环烷油的良溶剂,甲醇和丙酮是环烷油的不良溶剂;IGC法测得随着温度的升高,环烷油的溶度参数从50℃的13.94(J/cm3)1/2逐渐降至80℃的13.21(J/cm3)1/2;利用相互作用参数与温度的关系,采用外推法可得到25℃时环烷油的溶度参数为14.38(J/cm3)1/2,这与14.50(J/cm3)1/2(根据表面张力-溶度参数关系式计算而得)基本一致。     

Über die Adsorption von Fettsäuren an Ionenaustauschern

Adsorption of Fatty Acids on Ion Exchangers The author examined the adsorption of saturated fatty acids C₁₀ to C₁₈ on strong- and weak-basic anion exchangers in the presence of n-hexane, acetone and 96% ethanol. The extent of adsorption on dried anion exchangers is small, and in nonpolar solvents, the effective capacity amounts to 5% of the theoretical capacity. With wetted resins, not the polarity of the solvents but the dissociation of the functional groups of the exchanger is the factor determining adsorption. Since the adsorbing ability of the exchanger is limited by the length of the fatty acid molecules, the effective capacity of strongly basic exchangers amounts only to one-third or a half of the theoretical capacity.     

1-甲基-3-(3-丙磺酸基)咪唑硫酸氢盐在一些溶剂中的溶解度(英文)

Ionic liquid 1-methyl-3-(3-sulfopropyl)-imidazolium hydrogen sulfate ([C3SO3HMIM][HSO4]) was synthesized and characterized by infrared spectroscopy (IR), nuclear magnetic resonance (1H and 13C NMR) and ultraviolet-visible (UV-Vis) spectra. Its thermal stability was also examined by thermogravimetric analysis (TGA) and a differential scanning calorimeter (DSC). The mole fraction solubilities of [C3SO3HMIM][HSO4]) in 12 selected solvents (n-pentane, n-hexane, n-heptane, benzene, toluene, ethylbenzene, acetone, 2-butanone, 3-methyl-2-butanone, tetrahydrofuran, ethyl acetate and dichloromethane) in the temperature range from 289.15 to 363.15 K were measured using a static analytical method and correlated with an empirical equation.     

Extraction of lipids from cotronseed tissue: I. Comparison of hexane-acetone-water,its nonqueous components and chloroform-methanol

Flaked cottonseed was extracted with chloroform-methanol-water, chloroform-methanol, hexane-acetone-water, hexane-acetone, hexane and acetone. Amounts of total material in the miscellae were greatest with chloroform-methanol-water and decreased to acetone in the order given above. The first three solvents extracted 6% more neutral oil and over 100% more lipophilic phosphorus than the latter three solvents. All solvents showed similar rates of extraction, each removed over 70% of extractables with the first of four passes.     

Isothermal Compressibility of Liquids at Low Pressures

A simple borosilicate glass compressibility cell was constructed which allowed the measurement of relative volumes of liquids to a precision of ± 0.00002. The relative volumes of water, acetone, n-hexane and neopentane were measured at 25°C at pressures to 70 atm. In addition the relative volumes of n-hexane were measured at 50°C. Isobaric thermal expansion coefficients were measured for acetone and n-hexane in a narrow temperature range near 25°C. The isothermal relative volume data were fitted to theTait equation from which the isothermal compressibilities of the four liquids were computed. The compressibilities were slightly different from the compressibilities calculated from high pressure literature data fits of the Tait equation     

Isothermal Compressibility of Liquids at Low Pressures

A simple borosilicate glass compressibility cell was constructed which allowed the measurement of relative volumes of liquids to a precision of ± 0.00002. The relative volumes of water, acetone, n-hexane and neopentane were measured at 25°C at pressures to 70 atm. In addition the relative volumes of n-hexane were measured at 50°C. Isobaric thermal expansion coefficients were measured for acetone and n-hexane in a narrow temperature range near 25°C. The isothermal relative volume data were fitted to theTait equation from which the isothermal compressibilities of the four liquids were computed. The compressibilities were slightly different from the compressibilities calculated from high pressure literature data fits of the Tait equation     

Influence of solvent type on dibenzothiophene adsorption onto activated carbon fiber and granular coconut-shell activated carbon

The adsorption behavior of dibenzothiophene (DBT) on an activated carbon fiber (ACF) and a granular coconut-shell activated carbon (GCSAC) in the solvents n-hexane, n-decane, toluene, and mixture of n-decane and toluene was investigated. The DBT adsorption onto both samples was more active in n-hexane than in n-decane. The lowest DBT adsorption was observed in toluene. Regardless of the type of activated carbons and solvents, all the isotherms fit the Freundlich equation better than the Langmuir equation. At low equilibrium concentrations of <2 mass ppm-S, GCSAC displayed greater capacity for DBT adsorption than did ACF in all the tested solvents. The adsorption kinetics of ACF and GCSAC in all the tested solvents were governed by a pseudo-second-order model.