分散液液微萃取PPCPs—三氯生
冷诱导分散液-液微萃取用于牛奶中三聚氰胺的检测[开题报告]
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毕业论文开题报告环境工程冷诱导分散液-液微萃取用于牛奶中三聚氰胺的检测一、选题的背景、意义2008年9月，国内爆发了三鹿问题奶粉事件，导致数百万名食用含三聚氰胺奶粉的婴幼儿患肾结石等病症住院治疗。
国家质检总局在全国紧急开展婴幼儿奶粉三聚氰胺含量专项检查。
由于三聚氰胺的含氮量高达66.63%，而目前测定牛奶中含蛋白质的含量是采用食品行业通行的“凯氏定氮法”，即通过测定食品中氮原子的含量而间接推算的方法，因此，三聚氰胺经常被不法生产者和销售商作为“蛋白精”用来提升牛奶中所谓蛋白质含量的指标。
三聚氰胺是一种重要的氮杂环有机化工原料，白色无味结晶粉末[1]。
这种化学品常被用于生产塑料、胶水和阻燃剂，在部分亚洲国家，它也被用于制造化肥。
不易被机体代谢，具有肾毒性与致癌作用。
大量动物实验表明，长期摄入三聚氰胺会造成生殖泌尿系统的损害，膀胱，肾结石，尿毒症和慢性肾衰竭，并可进一步诱发膀胱癌，对消费者造成了极大的危害。
卫生部等五部门立即颁布了“2008年第25号乳制品及含乳食品中含三聚氰胺临时管理限量值规定”的公告，规定：婴幼儿配方乳粉中三聚氰胺的限量值为1 mg/kg液态奶（包括原料乳），奶粉及其他配方乳粉中三聚氰胺的限量值为2.5 mg/kg。
因此，建立快速的检测方法以确保食品的安全十分必要。
样品预处理是色谱试验成功的关键步骤，由于真实样品组成复杂，且待测挥发性物含量一般较少，所以要求样品预处理方法既能较好的将待测物同其他物质分离，又有较高的富集能力。
传统的样品前处理方法，如液液萃取，索氏萃取，层析、蒸馏及吸附等，普遍存在操作繁琐耗时，需要使用大量对人体和环境有毒、有害的有机溶剂，以及难以实现自动化等缺点，因此，发展省时高效、有机溶剂耗用量少的样品前处理新技术一直是分析化学研究的一个热点领域[1-4]。
为节省时间,减轻劳动强度,减少样品用量,实现样品前处理的自动化、在线化,以及尽量减少有机溶剂的使用，近年来发展起来了多种新型样品前处理技术，例如固相萃取( SPE)[5]、分子印迹技术(MIT)[6]、固相微萃取( SPME)[ 7 ]、悬滴微萃取( SDME)[ 8] 、基于中空纤维的液相微萃取(HF-LPME)等。
水环境中PPCPs检测技术及风险评价研究进展
第！4卷第1期Vol . 34 No . 1水资源保护WATER RESOURCES PROTECTION2018年1月Ja n . 2018DOI :10. 3880/j . issn . 1004 -6933. 2018. 01 13水环境中PPCPs 检测技术及风险评价研究进展姚晶晶\吴东海2!陆光华1!2,周超2!沈兴厚3(1.西藏农牧学院水利土木工程学院，西藏林芝860000;2.河海大学环境学院，江苏南京210098;3.河南省水文水资源局，河南郑州450004)摘要：概述了目前水环境中药物及个人护理品（PPCPs )的检测技术，对比分析了常用的水样前处理 方法和仪器分析技术的原理、优缺点，介绍了 PPCPs 的风险评价体系，总结了人体健康风险和生态 风险的评价方法，并综述了不同PPCPs 的风险水平。
指出多技术联合、精准定量的检测技术和综 合风险评价方法是今后环境领域PPCPs 研究的重点。
关键词！药物及个人护理品；前处理；仪器分析技术;人体健康风险；生态风险中图分类号：X 830 文献标志码：A 文章编号= 1004-6933 (2018)01 -0076 -07Research progress of aquatic PPCPs detection technology and risk, assessmentYAO Jingjiiig 1，WU Donghai 2，LU Guanghua 1，2，ZHOU Chao 2，SHEN Xinghou 3(1.College of Hydraulic and Civil Engineering ，Tibet Agriculture and Animal Husban Linzhi .60000，China ; 2. College of Environment ，Hohai University ，Nanjing 210098，China ; 3. Hyd r+0#7and Water Resources Bureau of Henan Province ，Zhengzhoo 450004，China )Abstract ： The detection technology of aquatic pharmaceuticals and personal care products ( PPCPs ) were summarized . The principles ，advantages and disadvantages of the sample pretreatment method and instrument analysis technology were a nalyzed and compared . The risk assessment systems of aquatic PPCPs were introduced and the methods of human health risks and ecological risk assessment were summarized . PPCPs was reviewed . It is pointed out tliat multi-technique combination ，precise quantitative de and comprehensive risk assessment method are the key points of PPCPs research in the Keywords ： pharmaceuticals and personal care products (PPCPs ); sample pretreatment ; instrument analysis technology ; human health risk ; ecological risk药物及个人护理品（pharmaceuticals andpersonal care products ，PPCPs )广泛应用于医药、工 业、畜牧业、农业、水产养殖等领域[1]。
PPCPs的环境污染状况及研究进展详解
麝香类物质对动物和人类也具有生态毒性作用。
硝基麝香 佳乐麝香（较大剂量） 具有较强的生物富集作用,容 渗入人体细胞 引起小鼠干细胞增重；有皮肤刺 激作用；明显抑制水生生物幼虫 的生长发育 表现出一定的血红细胞毒性
芬檀麝香
吐纳麝香
硝基麝香与多环麝香-存于海底贝 类腮中的
明显抑制水生生物幼虫的生长发 育；引起试验小鼠急性肝损伤
3、消炎镇痛药
• 消炎镇痛药是被人类使用最多的一大类药物,属于家庭常 备药物。它们种类繁多,有些是处方药(如双氯芬酸等) , 而有些则可以在普通药店即可购买(如芬必得、双黄连口 服液等) 。由于巨大的生产和使用量,消炎镇痛药在环境 中残留的情况尤为突出,许多文献报道了它们在环境中残 留的种类及浓度。
• 当前水环境中有机物的微量检测主要还是通过色谱检测完 成的，对于PPCPs的分析检测常用到的有：
气相色谱与质谱技术（GC/MS） 高效液相（HPLC） 质谱联用的分析技术（HPLC/MS）
• Yoon对水中常见的PPCPs进行研究，根据它们logKow值不 同把它们分成两类：
第一类物质极性强、不易挥发、亲水性，采用HPLC/MS检测； 第二类物质极性弱、易挥发、憎水性，采用GC/MS检测。
六、PPCPs的检测
• 由于水环境中PPCPs的浓度较低，要准确了解其污染水平， 必须建立一套能够精确到ng/L级的PPCPs检测方法。完整 的检测过程包括： 水体样品 的采集 浓缩富集 检测
废水中药品及个人护理用品(PPCPs)的去除技术研究进展
废水中药品及个人护理用品(PPCPs)的去除技术研究进展废水中药品及个人护理用品(PPCPs)的去除技术研究进展引言：随着工业化和城市化的快速发展，人类活动产生的废水中含有大量的药品及个人护理用品(PPCPs)。
这些化合物对环境和人体健康构成潜在风险。
为了净化废水和保护环境健康，研究人员开展了各种技术研究，以去除废水中的药品及个人护理用品。
本文旨在综述各种技术在该领域的研究进展，并提出未来的研究方向。
一、废水中药品及个人护理用品的来源和潜在危害1. 药品和个人护理用品的种类和用途目前市场上常见的药品和个人护理用品包括抗生素、镇痛剂、激素、抗癌药物、香水、洗发水、洗衣粉等。
这些物质广泛应用于医疗、家庭、美容等方面。
2. PPCPs的进入环境途径PPCPs通过多种途径进入废水系统，其中包括人类排泄、医疗废物的处理、药物生产和使用过程中的泄漏和废水排放，以及家居和农业用水系统中的直接释放。
3. PPCPs对环境和人体健康的潜在影响研究表明，PPCPs在环境中的存在可能导致水体中的生态系统失衡，对水生生物和陆地生态系统产生毒性效应。
此外，长期暴露于PPCPs可能对人体健康产生不良影响，如内分泌干扰、细胞毒性、致突变性等。
二、常用的废水处理技术及其去除效果1. 活性炭吸附技术活性炭是一种具有强吸附性能的材料，广泛用于废水处理和水质净化领域。
研究表明，活性炭对药品和个人护理用品具有较好的去除效果。
2. 生物降解技术生物降解技术利用微生物降解废水中的有机物。
生物降解技术可通过使用具有降解能力的微生物、调节环境条件等方式去除废水中的药品和个人护理用品。
3. 高级氧化技术高级氧化技术利用自由基或氧化剂，在氧化、还原等化学反应中去除水中的有机污染物。
典型的高级氧化技术包括过氧化氢、紫外光催化氧化、臭氧氧化等。
研究表明，高级氧化技术对PPCPs的去除效果显著。
4. 光催化技术光催化技术通过利用半导体材料吸收太阳光能，产生电子-空穴对，从而引发光催化反应。
分散液液微萃取_高效液相色谱法测定环境水样中2_4_二氯酚
本文将 Ｄ 并 结 合 高 效 液 相 色 谱 －紫 外 检 测 法 Ｌ ＬＭＥ 方 法 应 用 于 环 境 水 样 中 ２， ４ －二 氯 酚 的 萃 取 ， （ ， 建立了 Ｄ 并 用 于 实 际 水 样 的 测 定， 结果 ＨＰ Ｌ Ｃ－ＵＶ） Ｌ ＬＭＥ－ＨＰ Ｌ Ｃ 测 定 环境水样中 ２， ４ －二 氯 酚 的 方 法 ， 令人满意。
图 １ Ｄ Ｌ ＬＭＥ Ｐ Ｌ Ｃ 分 析 污 水 中 ２， ４ －Ｈ －二 氯 酚 的 色谱 图 Ｆ ｉ ． １ Ｃ ｈ ｒ ｏ ｍ ａ ｔ ｏ ｒ ａ ｍ ｓ ｏ ｆ ２， ４ ｄ ｉ ｃ ｈ ｌ ｏ ｒ ｏ ｈ ｅ ｎ ｏ ｌ ｂ Ｄ Ｌ ＬＭＥ Ｐ Ｌ Ｃ ｉ ｎ ｗ ａ ｓ ｔ ｅ ｗ ａ ｔ ｅ ｒ － －Ｈ ｇ ｇ ｐ ｙ
采样、 富集、 分 离 于一 体 的 新型样品 萃 取 富 集 技术 。 可 以 达 到 很 高 的 富 集 倍 数 和 萃 取 效 率 。 此方法 具有操
８］ ， 快速 、 费用低、 对 环境 友 好 等 优 点 ［ 作简单 、 Ｄ Ｌ ＬＭＥ 方法 结合 各 种分 离 检测 技术 已 成 功应 用 于 环境中 多 ７］ ９］ １ ０］ １ １］ 、 、 、 环 芳 烃［ 酞 酸 酯［ 多 溴 联苯 醚 ［ 金 属 钒［ 等的分 离 分析 。
２ ０ １ ０ ０ ３ １ ２ ２ ０ １ ０ ０ ５ ０ ４ － － 修回 日期 ： － － 收稿日期 ： ） 基金项目 ：四 川省 教育 厅 重点 课 题 资 助 （ Ｎ ｏ ． ０ ９ Ｚ Ａ ０ １ ６ 男， 硕士， 教授 ， 主 要从事 环境 化学 方 面 的研究 ． ＊ 通讯作者 ：杨 迎 春 ，
（ ） ；（ ） ／ ） ／ ａ ｂ ｅ ｆ ｏ ｒ ｅ ｓ ｉ ｋ ｉ ｎ ｂ ａ ｆ ｔ ｅ ｒ ｓ ｉ ｋ ｉ ｎ ｗ ｉ ｔ ｈ １ ０μ Ｌ；（ ｃ ａ ｆ ｔ ｅ ｒ ｓ ｉ ｋ ｉ ｎ ｗ ｉ ｔ ｈ ２ ０μ Ｌ． ｐ ｇ ｐ ｇ ｇ ｐ ｇ ｇ
离子液体分散液相萃取
（R.-S. Zhao, L. L. Zhang, et. al. Anal Bioanal Chem, 2011, 399:1287–1293）
2.1.2 IL-DLPME-HPLC-UV分析环境水样中的DDT及其代谢产物
实际环境水样的色谱图
（R.-S. Zhao, L. L. Zhang, et. al. Anal Bioanal Chem, 2011, 399:1287–1293）
80 60 40 20 0 0 5 10 15 20 25 Centrifuging time (min) 30
(Ru-Song Zhao, Xia Wang, et al. Chin Chem Lett, 2011, 22, 97-100 )
2.2.2 温控离子液体DLPME-HPLC-MS-MS分析水样中HBCDs LOD: 0.1ng/mL; 线性范围：1-100ng/mL (HBCDs总浓度
2.3.2 IL/IL-DLPME-HPLC-ESI-UV分析环境水样中的菊酯类农药
(Ru-Song Zhao, Xia Wang, et al. J. Sep.Sci., 2011, 34, 830–836)
2.3.2 IL/IL-DLPME-HPLC-ESI-UV分析环境水样中的菊酯类农药
(Ru-Song Zhao, Xia Wang, et al. J. Sep.Sci., 2011, 34, 830–836)
实际样品分析
样品图
(Ru-Song Zhao, Xia Wang, et al. J. Sep. Sci., 2010, 33, 1842-1848)
2.2.2温控离子液体DLPME-HPLC-MS-MS分析水样中HBCDs
液相预处理方法汇总
液相色谱检测前处理方法织取10g草莓样品于50mLPPTE离心管中，加入10mL乙腈，振荡器上以200rpm的转速振荡30min 后,加入3g氯化钠和5g无水硫酸镁，剧烈手摇30s。
然后将盛装样品的离心管在离心机离心5mi n（离心力RCF=1006g），取1.5mL 上清液转入含有50mgPSA+50mgC i8+150mgMgSO4的2mL离心管。
充分振荡混匀后将混合液离心3mi n（离心力RCF=7155g ），吸取上清液0.5mL过0.22卩m有机滤膜后进UPLC-MS/MS 检测。
［QuEChERS-超咼效液相色谱-串联质谱法同时测定草莓中85种农药残留］2、加速溶剂萃取技确称取均质后的样品2.50g于50mL塑料离心管中，加入3 mL水涡旋混合1min，再加入 5mL 5 %（v/v ）甲酸乙腈涡旋混合1 min，超声提取10min。
加入Won dapokQuEChERS多兽残专用提取包4g，剧烈振摇1 min，于10 C 以8000r/mi n 下离心10min。
取1 mL上清液转移至Won dapokQuEChERS多兽残专用净化包中，涡旋混合 1 min ,12000r/min下离心5min。
取上清液，过0.22呵微孔滤膜，取滤液进行LC-MS/MS 分析。
［分散固相萃取-液相色谱—串联质谱法测定常见动物源性食品中42种兽药残留］称取5.00 g样品于50 mL玻璃离心管中，力廿20 mL乙酸乙酯，涡旋，超声提取15 min，5000 r / min离心5 min，移岀上清液至100 mL旋转蒸发瓶中，剩余残渣再加入20 mL乙酸乙酯，重复提取1次，合并上清液，旋转蒸发至近干。
加入1 mL 甲醇水溶液（80: 20，V / V），涡旋30 s，过CaptivaND Lipids小柱净化，收集液体，上机检测。
［超高效液相色谱一四极杆/静电场轨道阱高分辨质谱筛查水产品中21种环境激素］术（ASE ）:①样品经匀浆，于4C避光保存备用。
分散液液微萃取
Dispersive by microvolume Saadat Rastegarzadeh Department of Chemistry,detection.Analysis of fungicide thiram in environmental and agricultural samples was performed.a r t i c l e i n f o Article history:Received 11February 2013Received in revised form 7May 2013Accepted 8May 2013Available online 23May 2013Keywords:ThiramDispersive liquid–liquid microextraction Microvolume spectrophotometrya b s t r a c tA novel and simple method for the sensitive determination of trace amounts of fungicide thiram is devel-oped by combination of dispersive liquid–liquid microextraction (DLLME)and microvolume UV–vis spectrophotometry.The method is based on the conversion of thiram to a yellow product in the presence of ethanolic potassium hydroxide and copper sulfate,and its extraction into CCL 4using DLLME technique.In this method the ethanol existing in ethanolic KOH plays as disperser solvent and a cloudy solution is formed by injection of only CCl 4as extractant solvent into sample solution.Under the optimum condi-tions,the calibration graph was linear over the range of 25–1000ng mL À1of thiram with limit of detec-tion of 11.5ng mL À1.The relative standard deviation (RSD)for 100and 500ng mL À1of thiram was 2.7and 1.1%(n =8),respectively.The proposed method was successfully applied to determination of thiram in water and plant seed samples.Ó2013Elsevier B.V.All rights reserved.IntroductionDithiocarbamates (DTCs)are a group of organosulfur com-pounds that have been extensively used as pesticides in agriculture and horticulture over several decades [1,2].DTCs can be catego-rized into three subclasses depending upon their carbon skeleton including dimethyldithiocarbamates (DMDs),ethylenebis (dithio-carbamates)(EBDs),and propylenebis (dithiocarbamates)(PBDs).Among these,thiram (tetramethyl thiuram disulfide)(Fig.1)is a well-known dithiocarbamate fungicide that has been in commer-cial use since 1925[3].Thiram is widely used to prevent crop dam-age in the field and to protect harvested crops from deterioration in storage or transport and is also used as a seed protectant to control anumber of fungal diseases [4].Therefore,it extensively applied as a foliar treatment on fruits,vegetables,ornamentals and turf crops from a variety of fungal diseases.In addition,it is used as an animal repellent to protect fruittrees and ornamentals from damage by rabbits,rodents,and deer.Thiram is also used in rubber industry,in the treatment of human scabies,as a sunscreen,and as a bacte-ricide in soap [5–7].Although the usability of this dithiocarbamate compound is unassailable,its increasing application results in1386-1425/$-see front matter Ó2013Elsevier B.V.All rights reserved./10.1016/j.saa.2013.05.020Corresponding author.Tel./fax:+986113331042.E-mail addresses:rastegarz@ ,rastegarz@scu.ac.ir (S.Rastegarzadeh).being released into the environment leading to contamination of water,soil,and food.These contaminants adversely affect the envi-ronment and have serious hazardous effect in the living organisms.The reported studies on rats showed that the exposure to thiram has harmful effects on hepatic system and skin such as skin lesions (e.g.hand eczema or dermatitis),hepatic dysfunctions,neurotox-icity and citotoxicity [8].The residual amounts of thiram in human diet in combination with nitrite represent the potential precursor for the formation of carcinogenic nitrosamine.Furthermore,it has been mentioned that in body,carbon disulfide is formed from the breakdown of thiram and contributes to the toxicity of thiram to the liver [9].According to the US EPA (Environmental Protection Agency),thiram is expected to be sufficiently mobile and persistent in some cases to reach surface waters in concentrations high enough to impact aquatic life [10].To evaluate the risks of its intensive use,the determination of thiram in environmental matrixes is necessary to assay the thiram residues.Various analytical methods have been reported for the determi-nation of thiram in different crop matrices and environmental samples,including mass spectrometry [3,5],high-performance liquid chromatography [10–12],spectrophotometry [7,13,14],gas chromatography [15],polarography and voltammetry [16–18]chemiluminescence analysis [6,8,19]and surface-enhanced Raman scattering spectroscopy [1].The sample preconcentration step which has attracted much attention in analytical procedure includes the extraction of inter-ested components from a sample matrix.The most popular pre-treatment methods are liquid–liquid extraction (LLE)and solid phase extraction (SPE).Nevertheless,these conventional extraction methods are laborious,time-consuming and require large volumes of samples and toxic organic solvents.In the past years,several techniques particularly microextraction have been developed for sample preconcentration,due to the many advantages which makes it more attractive with respect to classic extraction approaches.Dispersive liquid–liquid microextraction (DLLME)as a considerable microextraction technique was emerged by Assadi et al.in 2006[20],which was based on a ternary solvent system like homogeneous LLE and cloud point extraction.In this method,an appropriate mixture of extraction and dispersive solvents is in-jected rapidly into an aqueous sample,resulting in the formation of a cloudy solution.The contact area between the extracting solvent and the sample solution is extremely large;thus,the extraction equilibrium is obtained rapidly.The advantages of DLLME are the usage of a small volume of organic solvents,simplicity of the oper-ation,rapidity,low cost,high recovery,high enrichment factor and environmentally friendly nature.Recently,this method has been applied for the determination of trace organic compounds and metal ions in environmental samples [21–27].In this work,a DLLME method followed by UV–vis spectropho-tometry equipped with a microcell is applied to sensitivedetermination of thiram.A colored organic phase is formed by reaction between thiram,ethanolic KOH and copper (II)sulfate and injection of CCl 4as extractant solvent.The important parame-ters,such as reaction conditions,the type and volume of extraction solvent and extraction time are investigated and optimized.Experimental ApparatusRecording the spectra and the absorbance measurements were made by a Jenway UV–vis spectrophotometer model 6320using quartz microcells with capacity of 350l L.A Metrohm 632(Swit-zerland)pH-meter was used to measure pH with a combined glass electrode.A model BHG HERMLE centrifuge (Germany)was used for the phase separation.ReagentsAll chemicals used were of analytical grade and double distilled water was used throughout.A stock solution of 100l g mL À1of thiram was prepared by dis-solving 0.0100g of pure thiram (Merck)in ethanol and diluting to 100mL in a volumetric flask.Working standard solutions were obtained daily by successive dilutions of this stock solution.A 0.10mol L À1ethanolic KOH solution (Merck)was prepared by dis-solving 0.561g of KOH in ethanol and diluting to 100mL.A stock solution of copper (II),1000l g mL À1,was prepared by dissolving of 0.391g CuSO 4Á5H 2O (Merck)in water and diluting to 100mL.Copper (II)working standard solutions were prepared daily by stepwise dilution of the stock solution.Dispersive liquid–liquid microextraction procedureFor DLLME under optimum conditions,an aliquot of the solu-tion containing thiram was placed in a 10mL volumetric flask,then 1mL of ethanolic potassium hydroxide solution (0.1mol L À1)and 5mL of 1l g mL À1of copper (II)were added.The resulting solution was then diluted to the mark with water and mixed thoroughly.After 10min the solution was transferred to a glass test tube with a conical bottom.Since ethanol (as disperser solvent)exists in solution,only 200l L of carbon tetrachloride (as extraction sol-vent)was rapidly injected into the sample solution by a microsy-ringe.After shaking manually,a cloudy solution (water,ethanol and CCl 4)was rapidly produced,and then the mixture was centri-fuged for 5min at 5000rpm.Accordingly,the dispersed fine drop-lets of the extraction phase deposited at the bottom of the conical test tube (170±5l L).The remained organic phase was removed with a microsyringe and subsequently placed into the quartz microcell and the absorbance was measured at 430nm against the blank.A blank solution was also run under the same procedure without adding any thiram.Preparation of plant seeds samplesAppropriate amounts of tomato,cucumber and watermelon seeds were weighed and placed into a 100mL beaker,then 30mL of ethanol was added,covered by a lid and stirred for 24h.The solution was then filtered and diluted to 50mL in a vol-umetric flask.An aliquot of the solutions was treated under the recommended procedure for DLLME and subsequent determina-tion of thiramcontent.Fig.1.Chemical structure of thiram (tetramethylthiuram disulfide).and Biomolecular Spectroscopy 114(2013)46–5047Results and discussionA dispersive liquid–liquid microextraction procedure based on the reaction of thiram in ethanolic KOH solution and in the pres-ence of copper(II)sulfate was developed for preconcentration of thiram.In order tofind the appropriate conditions for DLLME,dif-ferent experimental parameters were studied and optimized using a thiram standard solution.Wavelength selectionIn order to perform quantitative analysis spectrophotometri-cally the maximum absorption wavelength should be established. Therefore,the sample solution containing different concentrations of thiram was examined according to the recommended procedure of DLLME and corresponding spectra of sedimented phase were recorded in the range of350–650nm.As seen in Fig.2,upon increasing thiram concentration the absorbance at maximum wavelength,430nm,was increased.Therefore this wavelength was selected for measuring the absorbance of the extracted phase throughout this study.Effect of ethanolic KOH solutionThe presence of ethanolic KOH has strong effect on developing the color product.For this purpose the influence of ethanolic KOH solution in the concentration range of0–0.05mol LÀ1was studied in DLLME procedure.As can be seen from Fig.S1in the absence of KOH the absorbance of sedimented phase is very low which indi-cates that the colored product has not been formed efficiency. However,the maximum absorbance due to high extraction effi-ciency was obtained at0.01mol LÀ1.Therefore,1mL of ethanolic KOH solution0.1mol LÀ1was added to10mL sample solution to achieve this concentration.The effect of volume of ethanolic KOH 0.1mol LÀ1was also studied in the range of0.2–4.0mL.No signif-icant effect was observed in volume range of0.5–2.0mL.Nature of the extraction solvent and disperser solventSince the ethanol(as a dispersive solvent)was provided by the addition of ethanolic KOH,the cloudy solution appeared with rapid injection of only the extraction solvent.Thus,the effect of type of extraction solvent on DLLME was studied.The characteristics of extraction solvent in DLLME are similar to conventional LLE,namely low solubility in water and high effi-ciency for extraction of the target analyte.Therefore,carbon tetra-chloride,chloroform,dichloromethane and cyclohexane were considered for this purpose.A cloudy solution and two-phase sys-tem was formed using these solvents,however in the case of car-bon tetrachloride the signal was higher and more reproducible. Therefore,carbon tetrachloride was selected as extraction solvent.Additional experiments showed that the injection of a mixture of CCl4and different disperser solvents including methanol,etha-nol,acetonitrile and acetone at different ratios decreased the extraction efficiency.As mentioned previously the disperser sol-vent(ethanol)exists in solution and further addition of this solvent caused part of carbon tetrachloride to be dissolved in disperser sol-vent and migrated into aqueous phase.For this reason,the dis-solved carbon tetrachloride could not be sedimented down and accordingly extraction efficiency was decreased.Finally,the sug-gested method was carried out only by injecting the extraction sol-vent and the solution was shaking manually after injection of carbon tetrachloride.Thereby,a cloudy solution was formed and the extraction occurred.Effect of extraction solvent volumeThe volume of carbon tetrachloride as extraction solvent has strong effect on the sensitivity due to its effect on enrichment fac-tor.For this purpose a series of experiments were carried out with different volumes of carbon tetrachloride in the range of200–1000l L.As it is observed in Fig.S2,the absorbance of organic phase was decreased by increasing of the CCl4volume.This could be due to the dilution effect which decreases in concentration of the extracted species in sedimented ing injection vol-umes less than200l L of CCl4lower volume of organic phase was obtained,so that the absorption signal could not be measured by spectrophotometerfitted with microcells.Thus,in order to achieve high enrichment factor and low detection limit value, 200l L of CCl4was selected as optimum extractant solvent volume throughout the experiments.Effect of copper(II)amountIn order to achieve highest extraction efficiency the effect of the copper(II)concentration in the range of0.1–0.8l g mLÀ1was investigated.The obtained results revealed that the absorbance increased with increasing of the copper(II)concentration up to 0.5l g mLÀ1and remained nearly constant above this value.There-fore,the concentration of0.5l g mLÀ1was chosen as the optimum amount of the copper(II)concentration.Effect of standing timeIt was found that the incubation time before injection of carbon tetrachloride has an effect on the formation of the colored product. Therefore the dependence of absorbance of sedimented phase upon time in the range of2–40min was studied under previously optimized conditions.The obtained results show a considerable increase in the analytical signal with incubation time up to 10min and remained constant above that.Thus the injection of extraction solvent was carried out10min after mixing of the reagents.Since the extraction solvent was injected to the solution and it appeared cloudy without the addition of disperser,for breaking up of organic phase intofine droplets[28–30],it was necessary to shake the solution after injection of extraction solvent.48S.Rastegarzadeh et al./Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy114(2013)46–50Accordingly,the effect of shaking time on the DLLME of thiram was investigated in the range of0–60s.The obtained results denoted that the highest extraction efficiency was achieved about10s and above that shaking time had no significant effect on the absor-bance of sedimented phase.As the cloudy solution appeared with-infirst few seconds the infinitely large surface area between extraction solvent and aqueous phase was achieved and the color product diffuses quickly into the extraction solvent.This is the remarkable advantage of DLLME technique.The influence of centrifugation time on DLLME of thiram was also studied.The results indicated that for a complete separation of organic and aqueous phase the mixture should be centrifuged for5min at5000rpm.Interference studiesThe effect of potential interference of cations and anions on the DLLME and determination of thiram using the proposed procedure was studied.An error of±5%in the absorbance reading was consid-ered tolerable.In these experiments,sample solutions containing of200ng mLÀ1of the thiram and different concentrations of other ions were treated under the recommended procedure using opti-mum conditions.The results given in Table S1indicate that themethod is more selective to thiram than a large number of cations and anions.Analyticalfigures of meritAfter optimization of all parameters,quantitative characteris-tics of the proposed method were studied.The linear dynamic range,correlation coefficient(r),repeatability,limit of detection (LOD)and preconcentration factor were determined to evaluate the method performance.The analytical characteristics of the opti-mized method summarized in Table1.The preconcentration factor for the suggested DLLME method is calculated by the ratio of the highest sample volume(10mL)and thefinal lowest volume (170l L).Thus,a preconcentration factor of about58.8was achieved using this procedure.Application to real samplesTo demonstrate the performance and validation of the present method,it was utilized to determine the thiram in two water samples,which were selected from Karun River(Khuzestan Prov-ince,Iran)and Tap water(Ahvaz,Iran).The tested water samples were found to be free from thiram according to the optimized pro-cedure.The recovery tests were performed by the analysis of the samples spiked with known amounts of thiram.The analytical data of this investigation are given in Table2,as can be seen,the thiram recovery for the spiked samples is quantitative(94.7–104.9%).The proposed method was then applied for the determination thiram in three plant seed samples preserved by thiram.In addi-tion for evaluation of the accuracy of the method,a comparison between results obtained by suggested method and HPLC[11] was performed.The obtained results from both methods were sta-tistically evaluated by performing Student’s t-test and F-test.As can be seen in Table3the values calculated were found to be less than tabulated values at95%confidence level indicating no signif-icant differences in the accuracy and precision of the recom-mended method and the HPLC.ConclusionsIn the present study a DLLME method has been employed for sensitive determination of thiram.Miniaturization of toxic organic solvent using dispersive liquid–liquid microextraction combined with microvolume UV–vis spectrophotometry allows the develop-ment of a green method which is environment-friendly.Besides simplicity of operation,rapidity,low sample volume,low cost and high preconcentration factor are some advantages of the sug-gested method.There is no need for additional dispersive solvent because ethanol provided by the addition of ethanolic KOH acts as a disperser too.A comparison between presented approach and previously reported method for the determination of thiramTable1Analytical characteristics of the presented DLLME method for determination of thiram.Parameter Analytical featuresLinear range(ng mLÀ1)(n=10)25–1000Correlation coefficient(r)0.9985Detection limit(ng mLÀ1)(3r,n=10)11.5Precision(RSD%for100and500ng mLÀ1,n=8) 2.7,1.1Preconcentration factor58.8Table2Determination of thiram in water samples by proposed method.Sample Added(ng mLÀ1)Found a(ng mLÀ1)Recovery(%)River water(Karun)0N.D b–250257.8±3.2103.1500524.4±5.9104.9Tap water(Ahvaz)0N.D–250241.1±2.796.4500473.6±5.394.7a Mean±standard deviation(n=5).b Not detected.Table3Determination of thiram in plant seed samples by proposed method.Seed sample Thiram found(mg gÀ1)a t-Test b F-test cProposed method HPLCTomato0.428±0.0130.451±0.016 1.93 1.51 Cucumber 1.114±0.033 1.152±0.040 1.27 1.47 Watermelon0.748±0.0210.726±0.025 1.17 1.42a Mean±standard deviation(n=3).b Tabulated t-value for four degrees of freedom at95%confidence level is2.78.c Tabulated F-value for(2,2)degrees of freedom at95%confidence level is39.Table4Comparison of the proposed method with other methods for determination of thiram.DetectiontechniqueLinear range(ng mLÀ1)LOD(ng mLÀ1)RSD(%)Ref.SERS a 3.3–400.0 2.0NG b[1]FI-CL c50.0–1000 5.0 2.6[6]Spectrophotometry0–24,000300 1.9[7]CL-ELISA d9.0–15009.0NG[8]HPLC–UV500–450088<5[10]HPLC–UV 5.0–600 1.0NG[11]Spectrophotometry500–2500330NG[13]Voltammetry240.4–144,258103.4 1.6[17]FI-CL7.5–25007.0 2.5[19]Voltammetry48–2400132–5.8[31]Spectrophotometry Up to20,000161NG[32]DLLME-UV–vis25–100011.5 1.1–2.7Thisworka Surface-Enhanced Raman Scattering.b Not given.c Flow Injection-Chemiluminescence.d Chemiluminescence-Enzyme-Linked Immuno-Sorbent Assay.S.Rastegarzadeh et al./Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy114(2013)46–5049is given in Table4.As can be seen in table the LOD of suggested method is better or comparable to many of the reported tech-niques.Furthermore the application of spectrophotometric detec-tion has merits of simplicity,cheapness and portability.This methodology gives good accuracy,low limits of detection and excellent precision which show its potentiality in analysis of thi-ram in environmental and agricultural samples.AcknowledgementThe authors are grateful to Shahid Chamran University Research Council forfinancial support of this work(Grant1391). Appendix A.Supplementary materialSupplementary data associated with this article can be found,in the online version,at /10.1016/j.saa.2013.05.020. References[1]X.Zheng,Y.Chen,Y.Chen,N.Bi,H.Qi,M.Qin,D.Song,H.Zhang,Y.Tian,J.Raman Spectrosc.43(2012)1374–1380.[2]D.Bohrer,P.C.D.Nascimento,H.M.Gomes,J.Agric.Food Chem.47(1999)212–216.[3]T.Cajka,K.Riddellova,P.Zomer,H.Mol,J.Hajslov,Food Addit.Contam.A28(2011)1372–1382.[4]A.L.Queffelec,F.Boisde,rue,J.P.Haelters,B.Corbel,D.Thouvenot,P.Nodet,J.Agric.Food Chem.49(2001)1675–1680.[5]A.Peruga,S.Grimalt,F.J.Lopez,J.V.Sancho,F.Hernandez,Food Chem.135(2012)186–192.[6]A.Waseem,M.Yaqoob,A.Nabi,Anal.Sci.25(2009)395–400.[7]V.K.Sharma,J.S.Aulakh,A.K.Malik,Talanta65(2005)375–379.[8]S.Girotti,E.Maiolini,S.Ghini,E.Ferri,F.Fini,Anal.Lett.41(2008)46–55.[9]V.K.Sharma,J.S.Aulakh,A.K.Malik,J.Environ.Monit.5(2003)717–723.[10]O.M.S.Filipe,M.M.Vidal,A.C.Duarte,E.B.H.Santos,J.Agric.Food Chem.56(2008)7347–7354.[11]J.S.Aulakha,A.K.Malikb,R.K.Mahajan,Talanta66(2005)266–270.[12]S.B.Ekroth,B.Ohlin,B.G.Osterdahl,J.Agric.Food Chem.446(1998)5302–5304.[13]O.M.S.Filipe,M.M.Vidal,A.C.Duarte,E.B.H.Santos,Talanta72(2007)1235–1238.[14]E.D.Caldas,M.H.Conceicao,M.C.C.Miranda,L.C.K.R.de Souza,J.F.Lima,J.Agric.Food Chem.49(2001)4521–4525.[15]Z.Vryzas,E.N.Papadakis,E.P.Mourkidou,J.Agric.Food Chem.50(2002)2220–2226.[16]D.K.Sharma,A.Gupta,R.Kashyap,Toxicol.Environ.Chem.93(2011)1319–1331.[17]M.A.Hernandez-Olmos,L.Agui,P.Yanez-Sedeno,J.M.Pingarron,Electrochim.Acta46(2000)289–296.[18]Y.G.Zhao,X.W.Zheng,Z.Y.Huang,M.M.Yang,Anal.Chim.Acta482(2003)29–36.[19]A.Waseem,M.Yaqoob,A.Nabi,Luminescence25(2010)71–75.[20]M.Rezaee,Y.Assadi,M.M.Hosseini, E.Aghaee, F.Ahmadi,S.Berijani,J.Chromatogr.A1116(2006)1–9.[21]S.Khodadoust,M.Hadjmohammadi,Anal.Chim.Acta699(2011)113–119.[22]Z.Gao,X.Ma,Anal.Chim.Acta702(2011)50–55.[23]X.Jia,Y.Han,X.Liu,T.Duan,H.Chen,Spectrochim.Acta B66(2011)88–92.[24]M.Moradi,Y.Yamini,A.Esrafili,S.Seidi,Talanta82(2010)1864–1869.[25]Q.Zhoua,N.Zhaob,G.Xie,J.Hazard.Mater.189(2011)48–53.[26]H.Sereshti,V.Khojeh,S.Samadi,Talanta83(2011)885–890.[27]A.N.Anthemidis,K.G.Ioannou,Talanta84(2011)1215–1220.[28]X.Wen,Q.Yang,Z.Yan,Q.Deng,Microchem.J.97(2011)249–254.[29]L.Fu,X.Liu,J.Hu,X.Zhao,H.Wang,X.Wang,Anal.Chim.Acta632(2009)289–295.[30]J.Skrlikova,V.Andruch,I.Balogh,L.Kocurova,L.Nagy,Y.Bazel,Microchem.J.99(2011)40–45.[31]C.Fernhndez,A.J.Reviejo,J.M.Pingarron,Anal.Chim.Acta305(1995)192–199.[32]A.Tunçeli,H.Bag˘,A.R.Türker,Fresen.J.Anal.Chem.371(2001)1134–1138.50S.Rastegarzadeh et al./Spectrochimica Acta Part A:Molecular and Biomolecular Spectroscopy114(2013)46–50。
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Acetone
ACN
mean ± SD mean ± SD mean ± SD
90.67 ± 1.1 55.05 ± 1.6 60.75 ± 7.2
四氢呋喃萃取效率最高！
17
分散液液微萃取的优化 萃取剂的选择
1
盐效应 4
2
分散剂的选择
3
萃取时间的影响
萃取时间的影响
萃取时间对目标物的萃取效果影响不大！
PPCPs：处方药和非处方 药，麝香、诊断剂、化妆品、 保健品、杀菌剂、遮光剂、 染发剂等。
3
PPCPs 的特点
PPCPs 概述
浓度低
污染
种类多 PPCPs 范围广
潜在 危害大
4
PPCPs 进入水体途径
PPCPs 概述
城市水循环体系中PPCPs的主要来源以及进入水体的途径
5
三氯生
三氯生，学名“二氯苯氧氯酚” 广谱抗菌剂
高等环境化学课程报告
分散液液微萃取 PPCPs — 三氯生
【汇 报 人】 【指导老师】 【汇报时间】
1
目录
1 PPCPs 概述 2 PPCPs 前处理方法 3 分散液液微萃取三氯生
2
PPCPs 定义
PPCPs 概述
药品和个人护理用品 Pharmaceutical and Personal Care Products — PPCPs
【原理】
分散液液微萃取相当于微型化的液-液萃取，是基于
三 目标元分析物在样品溶液和萃取剂之间平衡分配的过程。
溶 剂 系 统
离心
9
PPCPs 前处理方法
【原理】
三 元 溶 剂 系 统
优点
操作简单快速、有机溶剂消耗低、回收 率和富集倍数高。广泛应用于痕量分析检测。
适用范围
亲脂性高或中等分析物。对于具有酸 碱性的分析物，通过调节pH，使其以非离 子状态存在。提高分配系数。
19
分散液液微萃取的优化 萃取剂的选择
1
盐效应 4
2
分散剂的选择
3
萃取时间的影响
盐效应
本实验不需加盐！
21
高等环境化学课程报告
谢谢观赏！ 敬请批评指正！
22
10
【影响因素】
PPCPs 前处理方法
11
高等环境化学课程报告
分散液液微萃取三氯生
12
分散液液微萃取三氯生 分散液液微萃取分离三氯生
称取目标化合物 萃取
分 散 剂
四 氢 呋 喃
水 / 四氢呋喃 / 四氯乙烷
离心
沉积相
混合
四 氯 乙 烷
萃 取 剂
13
分散液液微萃取的优化 萃取剂的选择
1
盐效应 4
2
分散剂的选择
3
萃取时间的影响
萃取剂 条件
萃取剂的选择
➢密度比水大； ➢不容于水； ➢对目标物有很高的萃取性能； ➢色谱峰形较好，杂峰少； ➢有两相形成。
不同萃取剂对三氯生的萃取率的影响
Analytes TCS
Recovery（%）
CHCl3
C2H2Cl4
CCl4
mean ± SD mean ± SD mean ± SD
ቤተ መጻሕፍቲ ባይዱ
PPCPs 概述 酶活性
洗涤用品
应用
清新剂
消毒剂
毒理
富集
内分泌干扰
6
高等环境化学课程报告
PPCPs 前处理方法
7
PPCPs 前处理方法
样品特点：在环境中浓度低，大多是药物是极性且分子量较小。
PPCPs的分析关键是样品的浓缩富集--萃取。
有机溶剂量少 操作简单 成本低 可实现选择性萃取
8
PPCPs 前处理方法
75.83 ± 0.7 99.94 ± 1.7 85.40 ± 4.5
四氯乙烷萃取效率最高，并且所需萃取剂的体积最小！
15
分散液液微萃取的优化 萃取剂的选择
1
盐效应 4
2
分散剂的选择
3
萃取时间的影响
分散剂的选择
不同分散剂对三氯生的萃取效率的影响
Analytes TCS
Recovery（%）
THF