酯硬化水玻璃旧砂中残留酯的提取与测定

酯硬化水玻璃旧砂及再生砂中的残留酯对再生砂的可使用性能有重要影响。本文旨在建立一种水玻璃旧砂及再生砂中的残留酯提取和检测方法。以乙醇、石油醚、丙酮等为溶剂,采用索氏提取器提取酯硬化水玻璃旧砂中残留酯,将提取物中的残留酯水解后,利用中和滴定法测定其中酸含量。通过酸碱滴定测试残留酯水解产物有机酸的量来反应残留酯的含量。结果表明,通过对提取溶剂、提取温度、提取时间、液固比的研究,在单因素试验基础上采用四因素三水平正交试验对提取条件进行优选,确定了最佳提取工艺:提取溶剂为石油醚,提取温度为80℃,提取时间1.5 h。这为水玻璃再生砂性能的评价奠定基础。

QuEChERS联用气相色谱法同时测定枸杞中21种拟除虫菊酯农药残留

目的建立QuEChERS联用气相色谱同时测定枸杞中21种拟除虫菊酯农药残留的方法。方法针对枸杞基质,优化QuEChERS技术中净化填料的用量,并考察所有目标农药的基质效应。采用DB-35毛细管色谱柱分离待测物,采用电子捕获检测器(ECD)测定,以保留时间定性,以基质匹配标准曲线定量。结果21种拟除虫菊酯在质量浓度为0.010~1.0μg/ml范围内呈现良好的线性关系,相关系数均大于0.9990,方法定量限在0.005~0.010mg/kg之间。空白样品3个水平的加标回收率均在80.14%~116.38%之间,相对标准偏差在0.38%~8.76%范围内。结论此法可应用于枸杞及枸杞制品中21种拟除虫菊酯农药残留检测和定量分析。

苹果中残留拟除虫菊酯检测的前处理方法研究

就苹果样品中残留拟除虫菊酯农药检测的前处理条件进行了系统筛选与分析研究，研究表明，采用丙酮：正己烷（1：1）复合溶剂、MAE法提取、弗罗里硅土净化的前处理方法，苹果样品中残留拟除虫菊酯农药测定回收率为86．9％-101．8％，检测精密度和灵敏度高，变异系数为3．28％-8．82％。

动物产品中17种有机氯、拟除虫菊酯残留同时测定的全自动固相萃取技术研究

本研究针对目前动物产品中有机氯、拟除虫菊酯残留检测干扰严重,必须进行繁琐的酸消化、硫酸磺化样品前处理问题,应用全自动固相萃取技术对动物产品中17种有机氯、拟除虫菊酯残留检测的样品前处理方法进行了系统的研究,对提取溶剂、固相萃取柱、淋洗液、洗脱溶剂及仪器分析条件进行了优化选择,建立了高效、快速、经济、安全的动物产品中有机氯、拟除虫菊酯残留同时检测的全自动固相萃取净化方法。经不同检测单位验证,该方法的加标回收率介于78.6%～103.0%之间,精密度(CV)为2.7%～12.1%,测定低限为0.005～0.010mg/kg,满足出口检测要求。

气相色谱法测定水体中3种拟除虫菊酯农药残留

建立了测定水体中3种拟除虫菊酯农药残留量的色相色谱法。样品经环己烷萃取后，无需K-D浓缩器浓缩，用浓硫酸消除杂质干扰后直接进样，采用毛细管拄、ECD检测器、外标法定量。该方法操作简单，最低检出浓度0．002～0．004mg／L，回收率为77．7％～86．1％。

气相色谱法测定酸奶中4种拟除虫菊酯农药的残留

采用液液萃取法提取、气相色谱电子捕获（EcD）检测器对4种拟除虫菊酯农药（联苯菊酯、氯氟氢菊酯、氯氰菊酯、氰戊菊酯）在酸奶体系中的残留进行测定。结果表明，4种拟除虫菊酯农药以0．50，0．75和1．00mg／L的3个添加水平时的检出限范围是0．004~0．013mg／L，标准曲线的相关系数大于0．999。前处理方法简单，GC分析时间为37min，4种农药在酸乳中的添加回收率为82．49％～111．66％。该方法快速、灵敏度高、各项指标均满足4种拟除虫菊酯在酸奶体系中残留检测的要求。

GC法测定富马酸替诺福韦二吡呋酯的残留溶剂

目的 :建立顶空毛细管GC法同时测定富马酸替诺福韦二吡呋酯原料药中乙醇、异丙醇、二氯甲烷、乙酸乙酯、四氢呋喃、N,N-二甲基甲酰胺、N-甲基吡咯烷酮7种残留溶剂的分析方法。方法 :采用Agilent DB-624色谱柱,FID检测器,二甲基亚砜(DMSO)为溶剂。结果 :在选定的色谱条件下,各溶剂峰均能良好分离,溶剂乙醇、异丙醇、二氯甲烷、乙酸乙酯、四氢呋喃、N,N-二甲基甲酰胺、N-甲基吡咯烷酮分别在相应浓度范围内与峰面积呈良好线性关系。各溶剂最低检测限符合要求。结论 :经方法学验证,本法可用于富马酸替诺福韦二吡呋酯的残留溶剂测定。

影响酯硬化水玻璃干法再生砂性能的主要因素

试验研究了残留水玻璃和残留酯对酯硬化水玻璃旧砂及其干法再生砂性能的影响。结果表明 ,残留酯是使酯硬化水玻璃旧砂及其干法再生砂可使用时间变短、再粘结强度下降的主要原因。因此 ,去除残留酯是再生酯硬化水玻璃旧砂的主要任务之一。而采用湿法再生或干法再生前对旧砂进行 32 0～ 35 0℃的加热处理 。

工业废水和城市污水中邻苯二甲酸酯残留分析

本文建立了利用固相萃取前处理技术和液相色谱法分析研究重点污染点源(包括工业废水和城市污水)中邻苯二甲酸酯污染残留的新方法,工业废水和城市污水中主要邻苯二甲酸酯残留为DBP和DEHP。

Determination of 10 Pyrethroids Pesticide Residues in Rice by GC-MS-MS

[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.

食品中30种有机氯和拟除虫菊酯农药多残留检测技术研究

目的 建立食品（蔬菜、水果、粮食、茶叶）中30种有机氯和拟除虫菊酯农药多残留快速检测方法。方法样品用乙睛提取、固相萃取Florisil小柱净化，双柱-ECD气相色谱法同时定性、定量测定30种有机氯和拟除虫菊酯农药残留。结果 30种农药在HP-5柱和DB-17柱上分离效果较好，其线性范围较宽，并在此浓度范围内显良好的线性关系（r=0．99～0．9999），在蔬菜、水果、粮食、茶叶中3个浓度添加水平平均回收率为66．5％～116．2％，变异系数为0．7％～14．2％，最低检出浓度为0．08～26p,g／kg。结论 方法准确，重现性、精密度好，杂质干扰少，且简便快速，成本低，适用范围广。该方法符合农药多残留测定方法要求。

Application of Molecular Distillation Process to Extend the True Boiling Point Curve of Petroleum Residues 400 ℃ ＋

True Boiling Point （TBP） distillation is one of the most common experimental techniques for determination of petroleum properties. The methods for performing TBP distillation experiments are described by ASTM D2892 and by ASTM D5236. However, these methods are established for petroleum fractions that reach temperatures up to 565 ~C. In this work, two petroleum residues were distilled in a falling film molecular distillation prototype and the data were used to obtain the extension of the TBP curve above a temperature of 565 ~C. It was possible to extend the TBP curve of both petroleum up to temperatures close to 700 ~C with consistency and continuity in comparison to the standard curve. In addition, an amount of raw material that was been treated as residue could be reused.

Residue curve maps of ethyl acetate synthesis reaction

The residue curve maps are considered as a powerful tool for the preliminary design of reactive distillation. The residue curve maps of ethyl acetate synthesis reaction were calculated based on the pseudo-homogeneous rate-based kinetic model and the NRTL activity coefficient model. The results show that the unstable node branch emerges from the ethyl acetate/water edge, moving toward the chemical equilibrium surface with the increase of Damkoeler value （D）, and the node reaches the ternary reactive azeotrope when D-∞ eventually. Conceptual design for the ethyl acetate synthesis of reactive distillation based on the residue curve maps is presented at last.

Statistical Analysis of Regularity of Pesticide Residues in Vegetables Produced in Inner Mongoli

[Objective]The paper was to study regularity of pesticide residues in vegetables produced in Inner Mongolia.[Method]Mathematical statistic analysis was carried out on 6 800 samples of veggies,fruits,leguminous vegetables,nuts and seeds produced in Inner Mongolia.[Result]The dominated vegetables in Inner Mongolia were green leafy vegetables,solanaceous vegetables and melon vegetables,and their yields accounted for 70%of the total vegetables production.Since 2003,with the rapid increase of detected vegetable numbers,the status of vegetable quality safety had entered into a new stage of sustainable steady after a rapid decline or periodic fluctuation,and the differences in safety levels were obvious,of which the range of exceeding standard rate of pesticide residues in solanaceous vegetables,melon vegetables and leguminous vegetables(about 55%of the total vegetables)was under 2%,with average values of 1.1%,1.6%and 3.1%,respectively.They belonged to stable type.The exceeding standard rate of pesticide residues in green leafy vegetables and Chinese cabbage group(about 30%of total vegetables)presented a decreasing trend year by year,wondering in the range of 7%-10%.They belonged to main risk type.The time period of exceeding standard of pesticide residues in root vegetables and cole vegetables was under predictable,and its exceeding standard rate in some years was over 5%(amplitude variation is over 15percentage points).They belonged to random risk type.The kinds of pesticides,which exceeding standard rate in vegetables were relatively intensive,presented variance in different vegetable species.70%of the pesticides belonged to intermittent over-limits and the probability was below 5%.About 20%tradition pesticides often exceeded standard and their probabilities were over 30%.The exceeding standard of organophosphorus and carbamates pesticides in vegetables presented a decreasing tend,while the risk of some new pesticides containing nitrogen element and high effective pyrethroids showed an increasing tendency.[Conclusion]The paper provided decision making services for agricultural management departments.

Research on Pesticide Residues of Cypermethrin in Lettuce

In order to find the effective method to reduce pesticide residues in vegetables, and promote the healthy development of vegetable industry. The paper used chlorothalonil, fenvalerate, dimethoate widely used pesticides as experimental material, using GC method to measure residual dynamics of vegetable pesticide. The results show that： fenvalerate, dimethoate, chlorothalonil pesticide residues in lettuce was higher than that tomato in the application day, respectively reach at 42.9%, 44.9%, 57.8%, pesticide degradation rate in open land were significantly higher than those in greenhouse within 5-20 days. The test showed that： the degradation of pesticide amount is in 8.77%r-19.64% within 1 days. The initial concentration of pesticides on vegetables are relevant with surface area of vegetable edible parts; the degradation speed of pesticide degradation rate in greenhouse vegetable is obviously slower than the open field vegetable; pesticide deposition phenomenon is an important factor affecting the pesticide residues in greenhouse.

Development on the Technique of Total Recovery of Benzoic Acid Residue

Benzoic acid residue is solid waste produced from the production of benzoic acid by oxidizing toluene.Because it contained important chemical raw materials such as benzoic acid,benzyl benzoate and fluorenone,it is necessary to recover them from the residue.In this work the technique featured with high efficiency evaporation and vacuum distillation was developed to obtain total recovery and utilization of the benzoic acid residue.By controlling the operation temperature at 260℃ and the pressure of 16kPa in the rising and falling film evaporators,heavy components separated efficiently from the residue can be polymerized and the light components consisting of 63% of the residue entered into a benzoic acid vacuum distillation column.Keeping the temperature of polymerization at(280±10)℃,coumarone resin was produced after adjusting the softening point according to the market requirements.Vacuum distillation was operated under the following conditions:top temperature at 186℃,top pressure of 16kPa,bottom temperature at 240-250℃,reflux ratio being 3︰1.Benzoic acid of 98% purity was distilled out from the column as a side stream and the bottom product was crude benzyl benzoate.By the developed technique,the benzoic acid residue was splitted into three products,benzoic acid,crude benzyl benzoate and coumarone resin without any surplus waste.

Persistence of Imidacloprid and β-Cyfluthrin Residue in Black Pepper （Piper Nigrum L.） under Malaysia Climatic Condition

Persistence behavior of imidacloprid and beta-cyfluthrin in black pepper was studied following application of formulation of Solomon at 0.6 （recommended dose） and 1.2 （double recommended dose） g a.i./ha for one pepper production cycle. The results also showed that the Solomon at 0.6 mL/L concentration significantly suppressed the pest infestation in pepper vines. Pepper vine treated with Solomon produce more berries compared to control and showed no phytotoxicity. Analytical procedure of Solomon active ingredient was validated prior to actual analysis. Satisfactory recoveries ranging between 87.6%-106.7% were obtained for the fortified pepper berries samples. Results showed low level of imidacloprid and beta-cyfluthrin residues in dried pepper berries ranging between 〈 0.01 mg/kg to 1.43 mg/kg and 〈 0.01 mg/kg to 1.612 mg/kg respectively. The half-life value period for imidacloprid were found to be 2.06 and 2.30 days and for beta-cyfluthrin, these values were observed to be 1.57 and 1.49 days respectively at recommended and double recommended dose. Imidacloprid and beta-cyfluthrin residue dissipated below the limit of quantification （LOQ） of 0.01 mg/kg after 7 and 9 days respectively at recommended and double recommended dose. Soil sample collected 15 days after the last spray did not show the present of Imidacloprid and beta-cyfluthrin residue at their detection limit of 0.01 mg/kg.

Analysis of Residues Formed during the Liquefaction Process of Wheat Straw

Wheat straw(WS) was liquefied to analyze the reaction process of WS under the acid-catalyzed conditions. WS was liquefied almost completely in the presence of ethylene carbonate/ethylene glycol(EC/EG) blend solvents within 40min at 150 ℃. The residues with different liquefaction time were investigated by SEM, FTIR, and XRD. The residues exhibited loose structure and rough surface due to the presence of stacked irregular platelets. The FTIR results demonstrated that lignin was more easily liquefied in the presence of EC/EG blend solvents than cellulose because the bands of cellulose were stronger and the bands of lignin were much weaker during the liquefaction process of WS. Moreover, the XRD result of all residues declared that WS was gradually liquefied, dissolved and decomposed to small fragments of lower molecular weight, and condensed in part in the later stage of liquefaction.

气相色谱法测定大米中7种拟除虫菊酯农药

目的建立同时测定大米中多种拟除虫菊酯农药的气相色谱测定方法。方法利用固相萃取(SPE)技术进行样品前处理,采用气相色谱对大米中联苯菊酯、甲氰菊酯、三氟氯氰菊酯、氟氯氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯进行检测,内标法定量。结果 7种拟除虫菊酯农药的回收率为89%~115%,相对标准偏差为0.5%~7.2%,最小检测限(LODS)在1.1μg/kg^4.8μg/kg。结论该方法前处理简单快速,分析成本低,回收率高,满足拟除虫菊酯农药残留的快速灵敏检测的要求。

GC-MS/MS法同时测定枸杞子中23种农药残留量

目的:建立枸杞子中23种农药残留量的GC-MS/MS测定方法,并对不同来源的12批枸杞子中农药残留量进行测定。方法:样品经乙酸乙酯提取浓缩后,采用GC-MS/MS方法在程序升温条件下分离,质谱多反应监测(MRM)模式下测定,内标法定量。结果:23种农药化合物质量浓度在0.64~954 ng·mL^(-1)范围内线性关系良好(r>0.998),三水平添加回收率在70%~120%范围内,重复性RSD均小于10%;各农药检测限均不超过0.01 mg·kg^(-1),满足农药残留分析要求。12批枸杞中10批样品检出农药残留,含量范围为0.01~0.76 mg·kg^(-1)。结论:该方法经方法学验证,可用于枸杞子中农药残留量的控制。