| Online extraction-chromatography is one of the most popular analytical techniques.As the complexity and diversity of the sample matrices,the number of the target analytes and the demand for rapid high-throughput analysis increase,the development of new online extractionchromatography analytical systems is of great significance.In this work,a dual solid-phase extraction(SPE)-ultra-high performance liquid chromatography(UHPLC)-MS/MS system was developed and applied to the trace determination of 62 drugs in water.A solid-phase dehydration extraction(SPDE)-ultra-high pressure supercritical fluid chromatography(UHPSFC)-MS/MS system was developed and applied to the rapid screening of 45 doping agents in urine for the first time.The supercritical fluid extraction(SFE)-supercritical fluid chromatography(SFC)system was firstly applied to the determination of vanillin and its analogues in vanilla pods.These new online extraction-chromatography analytical techniques can simplify the analysis procedures and reduce manual operations,which help to shorten the analytical time,reduce the analytical errors and improve the sensitivity,precision as well as accuracy.Therefore,these online systems show promising prospects to become useful analytical tools and obtain widely development and application.The main contents and results are as follows:1.An online dual SPE-UHPLC-MS/MS system was developed and applied to the trace analysis of 62 drugs in water.When explored the characteristics of the system,the system realized the cross-use of two SPE columns,achieveing an analytical time of 14 min;the injection volume reached to 20 mL without sample loss;and the chromatographic peaks remained sharp and symmetrical under different desorption conditions.The sensitivity of the method reached to ng/L with the limits of detection(LODs)and limits of quantitation(LOQs)in the range of 0.00119-0.623 ng/L and 0.00475-2.49 ng/L,respectively.The linear correlation coefficients(r)of the standard curves were ?0.9929,the recoveries ranged from 80.7 to 119.9%,and the RSDs% of the intra-day and inter-day precisions were within 10.6% and 15.6%,respectively.All the results met with the requirements of the method validation.This online method was more sensitive,accurate,fast and efficient when compared with other methods.2.An online SPDE-UHPSFC-MS/MS analytical system was developed and applied to the rapid screening of 45 doping agents in urine for the first time.The system introduced an automatic dehydration proceduce and a pre-column dilution step,overcoming the bottleneck of UHPSFC that could not analyze aqueous samples directly.All the target compounds showed good linearities with linear correlation coefficients(r)?0.9928.The measured LODs and LOQs were in the range of 0.0380 ng/L-1.24 ?g/L and 0.125 ng/L-4.09 ?g/L,respectively;the accuracies were between 80.8 and 119.7%;intra-day and inter-day precisions were within 10.8% and 15.4%,respectively,which met the requirements of the method validation.This online method could reduce the matrix effects and improved the sensitivity and accuracy when compared with other methods.3.The online SFE-SFC system was applied to determine vanillin and its analogues in vanilla pods for the first time.The online SFE-SFC system enabled the fully automatic extraction and the direct injection of the extract to the chromatographic analysis,saving time and effort.The SFE conditions were optimized systematically by several single factor designs and a Box-Bohnken design.The relative extraction efficiencies of the four tested substances reached the range of 84.7-90.6%.The LODs and LOQs were 0.3368-1.424 ?g and 1.123-4.747 ?g,respectively.The linearities of the standard curves were good(r?0.9975)and the intra-day and inter-day precisions(RSDs%)were within 5.9% and 7.6%,respectively.The recoveries were 76.1-88.9%.All of them met with the requirements of the method validation.When compared with other methods,the extraction efficiencies of this online method were higher. |
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