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建立了水果、蔬菜中抗蚜威残留的荧光检测-高效液相色谱法。样品以乙腈提取,固相萃取氨基小柱(LC-NH2)净化,Waterscarbamateanalysis(3.9mm×150mm,4μm),V(甲醇)∶V(水)∶V(乙腈)=16∶68∶16为流动相,柱温30℃,流速为1.5mL/min进行分离,用荧光检测器进行检测,激发波长和发射波长分别为317nm,392nm。回收率在98.5%~105.4%,相对标准偏差为3.0%~4.6%,检出限为0.01mg/kg。 相似文献
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A flow-injection chemiluminescence (CL) method for the determination of melatonin based on the CL reaction of melatonin with hydrogen peroxide and sodium hypochlorite (NaOCl) in a basic alkaline solution was developed. The possible CL mechanism has been discussed, and a proposal for the reaction pathway was given that singlet oxygen was clarified to be produced in this reaction system and was responsible for the CL emission. Under the optimized conditions, the linear concentration range of application was 1.0×10^-7-2.5 × 10^-4 moloL-I with a de- tection limit of 5.0 ×10^-8 moloL-1 (S/N= 3). The relative standard deviation for eight repeated measurements of 1.0×10^-6 mol·L^-1 melatonin was 2.8%. The interferences of several important biological substances, some indole compound, cations and anions were studied. No interference was found for the anions, glucose, starch, most of cations and low concentration (less than 3.0 × 10^-6 mol·L^-1) of some biological substances and indole compound. The method was applied to the determination of melatonin in rat pineal gland and drug with satisfactory results. The sample throughput was 90 injections per hour. 相似文献
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Based on the micelle synergism mechanism, a chemiluminescence (CL) flow system for the determination of sulfite was described. The CL signal generated from the reaction of chlorate with sulfite in acidic solution was very weak, while the interfusion of sodium dodecylbenzenesulfonate (SDBS) resulted in a highly chemiluminescent intensity. The major goal of this work was to investigate and develop the SDBS rnicelle synergetic CL system. The mechanism was proposed and proved by spectrometry. The results indicated that the unique structure of SDBS micelles prorooted the aggregation of rhodamine 6G (Rh6G) and a much easier energy transfer, leading to a marked shift to red in the CL emission. This CL system was developed for the determination of sulfite and the concentration of sulfite was proportional to the CL intensity in the range of 5.0× 10^-8--1.0× 10^-5 mol/L with the detection limit of 1.7×10^-8 mol/L (S/N=3). The relative standard deviation was 3.3% for 1.0×10^ 6 mol/L sulfite solution with eleven repeated measurements. This method was successfully applied to the determination of sulfite in powder sugar. 相似文献
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