【摘要】：目的由于水果樣品組成復(fù)雜,需要在色譜分析之前,對樣品進行固相萃取前處理以去除雜質(zhì),濃縮痕量目標(biāo)物。為了克服傳統(tǒng)的填充型萃取柱難以重復(fù)使用、操作繁瑣的缺點,構(gòu)筑了一種可重復(fù)使用的以甲基丙烯酸異辛酯為單體的疏水作用整體柱,結(jié)合高效液相色譜,建立了水果中除蟲脲和氟鈴脲的分析測定方法。方法1以甲基丙烯酸異辛酯(EHMA)為單體,乙二醇二甲基丙烯酸酯(EDMA)為交聯(lián)劑,在不銹鋼柱管(10 mm×4.6 mm,i.d.)中通過原位聚合反應(yīng)合成poly(EHMA-co-EDMA)整體柱。實驗考察了致孔劑的種類、致孔劑的比例、單體和交聯(lián)劑的比例對整體柱性能的影響,并對整體柱的機械強度、表面形貌和比表面積等參數(shù)進行表征。2將合成的poly(EHMA-co-EDMA)整體柱作為固相萃取吸附劑用于水果中除蟲脲和氟鈴脲殘留的前處理。實驗優(yōu)化了固相萃取主要的影響參數(shù),包括上樣流動相種類(純水、5 mmol/L和10 mmol/L乙酸銨緩沖溶液、0.1%和0.5%甲酸溶液)、上樣流速(0.1 m L/min、0.3 m L/min和0.5m L/min)、洗脫流動相種類(甲醇、乙腈、0.5%和1.0%甲酸乙腈)、洗脫流速(0.3 m L/min、0.5 m L/min、1.0 m L/min)。3在最佳實驗條件下,對方法的線性范圍、檢出限、定量限、回收率和精密度等分析特征量進行驗證。此外,在相同條件下通過同一根poly(EHMA-co-EDMA)整體柱不同使用次數(shù)固相萃取除蟲脲和氟鈴脲得到的色譜峰峰面積,計算相對標(biāo)準(zhǔn)偏差,評價該吸附劑的重復(fù)性。結(jié)果1實驗選擇致孔劑十二醇和N,N-二甲基甲酰胺(DMF)的比例為5:1(V/V),單體和交聯(lián)劑比例為1:5(摩爾比),在60℃下反應(yīng)16 h制得poly(EHMA-co-EDMA)整體柱,該整體柱柱床均勻、連續(xù)多孔,比表面積為164.01m2/g。2將poly(EHMA-co-EDMA)整體柱作為固相萃取吸附劑結(jié)合高效液相色譜對水果中除蟲脲和氟鈴脲進行分析測定。實驗在0.1 m L/min流速下以5 mmol/L乙酸銨緩沖溶液為上樣流動相,在流速為1.0 m L/min條件下以乙腈為洗脫流動相將目標(biāo)物洗脫后,進C18柱分析。3該方法在0.1?50.0?g/m L范圍內(nèi)線性關(guān)系良好,相關(guān)系數(shù)(r)≥0.998,對除蟲脲和氟鈴脲的檢出限和定量限分別為:0.0072,0.009 mg/kg和0.024,0.03 mg/kg,在濃度為0.03 mg/kg、0.3 mg/kg和1.5mg/kg,3個水平的加標(biāo)回收率為89.5%~102.1%,日內(nèi)和日間相對標(biāo)準(zhǔn)偏差≤6.83%。Poly(EHMA-co-EDMA)整體柱第1次、第25次和第75次使用,除蟲脲和氟鈴脲色譜峰峰面積的相對標(biāo)準(zhǔn)偏差均小于5.2%。結(jié)論基于poly(EHMA-co-EDMA)整體柱作為固相萃取吸附劑結(jié)合高效液相色譜,建立水果中除蟲脲和氟鈴脲殘留的分析測定方法,滿足水果中除蟲脲和氟鈴脲的常規(guī)分析測定要求。Poly(EHMA-co-EDMA)整體柱不僅對水果中的農(nóng)藥具有良好的凈化作用,而且與傳統(tǒng)的一次性使用固相萃取吸附劑相比制備簡單、重復(fù)性良好,可重復(fù)使用75次以上。
[Abstract]:Objective due to the complex composition of fruit samples, it is necessary to pretreat the samples with solid phase extraction before chromatographic analysis to remove impurities and concentrate trace targets. In order to overcome the disadvantages of the traditional packed extraction column which is difficult to reuse and difficult to operate, a hydrophobic monolithic column with isooctyl methacrylate as monomer was constructed, which was combined with high performance liquid chromatography (HPLC). A method was established for the determination of diflufluuron and fluoridias in fruit. Methods 1 using isooctyl methacrylate (EHMA) as monomer and ethylene glycol dimethacrylate (EDMA) as crosslinking agent, a stainless steel column tube (10 mm 脳 4.6 mm,i.d.) was prepared. Poly (EHMA-co-EDMA) monolithic column was synthesized by in situ polymerization. The effects of the types of pore-forming agents, the proportion of pore-forming agents and the ratio of monomer to crosslinking agent on the properties of the monolithic column were investigated, and the mechanical strength of the monolithic column was also investigated. The surface morphology and specific surface area were characterized. 2 the synthesized poly (EHMA-co-EDMA) monolithic column was used as a solid phase extraction adsorbent for the pretreatment of fluoridias and fluoridias in fruit. The main parameters of solid-phase extraction were optimized, including the types of mobile phase (5 mmol/L pure water and 10 mmol/L ammonium acetate buffer solution 0.1% and 0.5% formic acid solution), the flow rate of 0.1 mL / min 0.3m L/min and 0.5m L/min, and the type of elution mobile phase (methanol). Under the optimum experimental conditions, the linear range, detection limit, quantitative limit, recovery rate and precision of the method were verified. In addition, under the same conditions, the peak area of the chromatographic peak was obtained by solid-phase extraction with the same poly (EHMA-co-EDMA) monolithic column for different times. The relative standard deviation was calculated and the repeatability of the adsorbent was evaluated. Results 1 the poly (EHMA-co-EDMA) monolithic column was prepared by reaction at 60 鈩，

本文編號：2214331