|
Sample preparation techniques (Sample pretreatment technology) refers to the sample preparation and sample decomposition and dissolution using appropriate methods, and components to be measured for extraction, purification and concentration of the process, so that the analytes into a measurable form, thereby performing quantitative and qualitative analysis. Sample pre-treatment is designed to eliminate matrix interferences and improve the method accuracy, precision, selectivity and sensitivity. Therefore, the analysis of the sample pre-treatment is the key to the detection process, if you choose pretreatment method properly, it may lead to the loss of certain components, interfering components can not be completely removed or introduce new impurities. However, as long as stable and reliable testing instruments, repeatability and accuracy of test results depends on the sample pre-treatment. A new method of detection sensitivity, and speed often the sample and the complexity of the process has a vital link. HPLC (High performance chromatography, HPLC) method is a chromatographic analysis of the material most commonly used in qualitative and quantitative analysis, a method which wears comparison with the classical liquid chromatography, analytical speed, high separation efficiency, high selectivity, high sensitivity and operational automation features. Therefore, high performance liquid chromatography in medicine, biochemistry, natural products, environmental analysis, food safety inspection of agricultural analysis and other fields is widely used. This paper uses a solid-phase extraction (SPE), cloud point extraction (CPE) and an ionic liquid dispersed phase microextraction (IL-DLME) such as fast and efficient sample preparation techniques for feed β-agonists and beverages red Erythrosine was purified with HPLC and its separation and detection. The main contents are as follows: a solid phase extraction combined with ultra performance liquid chromatography method for simultaneous determination of feed Cimaterol, salbutamol, terbutaline and ractopamine solid phase extraction combined with ultra performance liquid chromatography (UPLC) Simultaneous determination of feed Cimaterol, salbutamol, terbutaline and Lecco dopamine approach. Feed mixed with methanol extraction, oscillation centrifuged and the supernatant after drying for MCX nitrogen purification column. Four kinds of β-agonists linear range of 0.05-1μg mL-1, correlation coefficients were higher than 0.999. The average recovery rate of 90.1% to 101.4% and the relative standard deviation is less than 8.0%. 2 solid-phase extraction combined with ultra performance liquid chromatography method for simultaneous determination of five β-agonists feed using solid phase extraction purification feed five β-agonists (dopamine hydrochloride, Cimaterol, salbutamol, terbutaline forest and ractopamine), and through the ultra-high performance liquid chromatography (UPLC) separation and determination of them. Feed mixed with methanol extraction, oscillation centrifuged, the supernatant was equal two: one directly after acidification over acidic alumina column with 1 mol L-1 hydrochloric acid - methanol (1/9, v / v) elution; another dry nitrogen with 2% aqueous acetic acid solution after dissolution over MCX column, 5% ammoniated methanol. Combination of two eluent, 40 ℃ under dry nitrogen, add 1.0 mL concentration of 10 mM sodium dihydrogen phosphate solution, measured after over 0.22μm membrane. Five kinds of p-doping in the linear range was 0.05-1μg ml-1, correlation coefficients were higher than 0.996. The average recovery rate 77.9% to 97.0% and the relative standard deviation is less than 4.3%. 3 point extraction and HPLC determination of erythrosine beverage with a non-ionic surfactant Triton X-114 in the beverage extracted erythrosine and then by HPLC with UV detector for detection, establish a method for detecting beverage erythrosine new analytical method. Added 10.0 mL were taken with different concentrations of the standard solution for cloud point extraction beverage, enrichment factor of 50. The linear range of 0.002-5μg mL-1, the correlation coefficient greater than 0.999, the detection limit (LOD) and limit of quantitation (LOQ) were 0.5 ng mL-1 and 1.5 ng mL-1. Average recovery of 86.5% to 97.1% and the relative standard deviation is less than 5.7%. 4 ionic liquid DLLME combined HPLC beverages erythrosine DLLME ionic liquid (IL-DLME) first used in conjunction HPLC determination beverages erythrosine . This technique chosen less volatile organic solvents ionic liquids as extraction solvent extraction and concentration in one set. Paper, the ionic liquid 1 - octyl-3 - methylimidazolium hexafluorophosphate ([C8MIM] [PF6]), and the amount of ionic liquid, the volume of methanol, the pH of the working solution, the extraction time and dissolution temperature were optimized. The linear range of 0.005-5μg mL-1, the correlation coefficient greater than 0.999, the detection limit (LOD) and limit of quantitation (LOQ) was 2.0 ng mL-1 and 6.0 ng mL-1. The average recovery rate 83.6% to 95.6% and the relative standard deviation is less than 8.4%. This method is simple, rapid, low cost, recovery and enrichment factor advantages.
|