發(fā)布時間：2018-05-19 02:21

  本文選題：分散固相萃取 + 分散液液微萃取�。� 參考：《河北大學(xué)》2017年碩士論文

【摘要】：隨著人民生活水平的提高和健康意識的增強(qiáng),有利于身體健康的茶飲品日益受到消費(fèi)者的喜愛,然而由農(nóng)藥殘留引起的茶葉安全問題也逐漸引起人們的關(guān)注。近年來,微萃取樣品前處理技術(shù)受到越來越多分析工作者的青睞,分散液液微萃取(DLLME)技術(shù)和固相微萃取(SPME)技術(shù)正是在這一環(huán)境下應(yīng)運(yùn)而生,因其具有簡單、快速、成本低和富集倍數(shù)高等顯著優(yōu)點(diǎn),已被廣泛應(yīng)用于各種樣品基質(zhì)中目標(biāo)分析物的提取。本文圍繞兩種微萃取技術(shù)展開其在茶葉基質(zhì)農(nóng)藥殘留檢測中的應(yīng)用研究。全文共包括3部分,具體內(nèi)容如下:1.對新型樣品前處理技術(shù)進(jìn)行了總結(jié),重點(diǎn)介紹了分散液液微萃取技術(shù)的原理、影響因素及其在食品分析中的應(yīng)用,頂空固相微萃取技術(shù)的原理及其在復(fù)雜樣品基質(zhì)中的應(yīng)用,以及農(nóng)藥殘留檢測技術(shù)。最后介紹了本文的研究背景和研究內(nèi)容。2.將分散固相萃取和分散液液微萃取(d-SPE-DLLME)相結(jié)合,并與氣相色譜-三重四極桿質(zhì)譜(GC-MS/MS)聯(lián)用,建立了快速測定茶葉中7種擬除蟲菊酯類農(nóng)藥殘留的方法。樣品經(jīng)乙腈提取,N-丙基乙二胺(PSA)和多壁碳納米管(MWCNTs)凈化,四氯化碳(CCl4)濃縮萃取,用GC-MS/MS分析。采用全發(fā)酵紅茶基質(zhì),對影響萃取的諸因素進(jìn)行了優(yōu)化。以乙腈為提取劑進(jìn)行分散固相萃取,在進(jìn)行分散液液微萃取時,以200μL CCl4為萃取劑,1 mL乙腈為分散劑,萃取時間1 min。結(jié)果表明,7種農(nóng)藥在10~500μg/kg濃度范圍內(nèi)線性關(guān)系良好,相關(guān)系數(shù)r~2在0.9991~0.9999之間,檢出限在0.11~3.01μg/kg之間。7種農(nóng)藥在四種茶葉(紅茶、綠茶、烏龍茶和黑茶)3個添加水平下平均回收率范圍分別為:82.7~111.8%、75.4~113.6%和82.6~107.1%,相對標(biāo)準(zhǔn)偏差(RSD)≤8.6%(n=5)。本方法具有簡單、快速、成本低和檢出限低的特點(diǎn)。應(yīng)用所建立的方法對12種市售茶葉樣品進(jìn)行檢測,共檢出5種擬除蟲菊酯類農(nóng)藥殘留。3.利用頂空固相微萃取(HS-SPME)與氣相色譜-三重四極桿質(zhì)譜(GC-MS/MS)聯(lián)用,建立了茶葉中9種酰胺類除草劑農(nóng)藥殘留的快速檢測方法。對萃取涂層種類、無機(jī)鹽種類、水用量、鹽用量、萃取溫度和萃取時間等固相微萃取條件進(jìn)行了優(yōu)化。結(jié)果表明,9種農(nóng)藥在50~1000μg/kg濃度范圍內(nèi)線性關(guān)系良好,相關(guān)系數(shù)r~2在0.9925~0.9999之間,定量限在1~50μg/kg之間。4種茶葉基質(zhì)中9種農(nóng)藥在3個添加水平下平均回收率范圍分別為:70.3~125.4%、85.2~118.7%和74.6~113.3%,相對標(biāo)準(zhǔn)偏差(RSD)≤17.4%(n=5)。該方法簡單、快速、靈敏度高并且重現(xiàn)性好,可滿足茶葉基質(zhì)中9種酰胺類除草劑農(nóng)藥殘留檢測的要求。
[Abstract]:With the improvement of people's living standard and health consciousness, the tea beverage which is beneficial to the health is becoming more and more popular by consumers. However, the safety of tea caused by pesticide residues has been paid more and more attention. In recent years, the pretreatment technology of microextraction samples is favored by more and more analysts. The dispersed liquid microextraction (DLLME) technology and solid phase microextraction (SPME) technology emerge as the times require in this environment because of its simplicity and rapidity. The advantages of low cost and high enrichment ratio have been widely used in the extraction of target analytes in various sample substrates. In this paper, two microextraction techniques were applied to the determination of pesticide residues in tea matrix. The full text includes 3 parts, the concrete content is as follows: 1. In this paper, the new sample pretreatment technology was summarized, and the principle, influencing factors and application in food analysis, headspace solid phase microextraction technology and its application in complex sample matrix were introduced. And pesticide residue detection technology. Finally, the research background and content of this paper are introduced. A rapid method for the determination of seven pyrethroid pesticide residues in tea was established by combining dispersive solid phase extraction with dispersible liquid microextraction (d-SPE-DLLME) and gas chromatography-quadrupole mass spectrometry (GC-MS / MS). The samples were purified by acetonitrile extraction (N- propyl ethylenediamine) and multiwalled carbon nanotubes (MWCNTs). CCl4) was concentrated and extracted by GC-MS/MS. The factors affecting extraction were optimized by using the whole fermented black tea substrate. Acetonitrile was used as extractant to disperse solid phase extraction, and 200 渭 L CCl4 was used as extractant and 1 mL acetonitrile as dispersant. The extraction time was 1 min. The results showed that the linear range of seven pesticides was 10 渭 g/kg, the correlation coefficient was between 0.9991 and 0.9999, and the detection limit was between 0.11 and 3.01 渭 g/kg in four kinds of tea (black tea and green tea). The average recoveries of Oolong tea and black tea were 1: 82.7% 111.8% and 82.6% and 107.1%, respectively, and the relative standard deviation (RSDs) 鈮，

本文編號：1908285