Study On The Applications Of Second-order Calibration Methods In Chinese Herbs And Food Safety

With the aid of chemometrics,physical and chemical information of material can be obtained among a larger number of data generated from high order equipment.Multiway calibration,one of the hotspots,is attracting more and more people's attention.By using "mathematical separation" to replace or enhance "physical or chemical separation",determination of analytes of interest can be realized even in the presence of unknown interferences.The development of second-order calibration theory is relatively mature,and it has been widely used in many fields like food,medicine,environment and so on.Food and drug safety is related with people's health closely.Chinese medicine is the treasure of our country,and has a long history.Therefore,this thesis mainly focuses on the fields of Chinese herbs and food safety,combining the second-order calibration with high order equipment to determinate the analytes of interest in traditional Chinese medicine and food system,the main contents are as follows:In Chapter 2,Umbelliferone and scopoletin both being classified as coumarin have been demonstrated to act as an antibacterial,anti-inflammatory,antirheumatic agent and to have positive effects on cholesterol metabolism.Tibetan medicine Saussurea laniceps(SL)and traditional Chinese medicine Radix angelicae pubescentis(RAP)belong to the families Compositae and Rutaceae,respectively,and have a good therapy in some diseases,such as rheumatoid arthritis,dysmenorrhea and so on.Thus,as the major active components of the two common medicines,umbelliferone and scopoletin are thought to be the most important bioactive markers for the basic quality control of SL and RAP.Therefore,an economical and simple method for simultaneous determination of umbelliferone and scopoletin is of great importance.Most methods in literature are based on liquid chromatography with different detectors,but there are some drawbacks of time-consuming,high-cost,and low sensitivity.A chemometrics-assisted excitation-emission matrix fluorescence method for simultaneous determination of umbelliferone and scopoletin in SL and RAP is presented in this work.Using the strategy of combining three-way excitation-emission fluorescence data with second-order calibration method based on the alternating trilinear decomposition(ATLD)algorithm,the simultaneous determination of umbelliferone and scopoletin in the two different complex systems was achieved successfully,even in the presence of unknown interferences.The preparation is simple due to the "second-order advantage",uses the "mathematical separation" instead of awkward physical or chemical separation.Satisfactory results have been achieved with the limits of detection(LOD)of umbelliferone and scopoletin being 0.06 ng mL-1 and 0.16 ng mL-1 and the average spike recoveries being 98.8±4.3%and 102.5±3.3%respectively.Experimental results implied the advantages of fast,low-cost,high sensitivity,indicating that the use of second-order calibration method coupled with excitation-emission matrix fluorescence is a promising tool for multi-component simultaneous determination in complex systems containing unknown interferences.In Chapter 3,Syringic acid exists in Chinese medicine Artemisia stelleriana and Radix isatidis and has many activities like antibacterial,antifungal and antiendotoxin.a-asarone is the main component of Chinese medicine Rhizoma acori tatarinowii.Pharmacological studies indicate that it has antibacterial,anti-inflammatory,sedative and expectorant activities.In this chapter,using the strategy of combining excitation-emission matrix fluorescence with second-order calibration methods based on parallel factor analysis(PARAFAC)algorithm and alternating normalization-weighted error(ANWE)algorithm,the simultaneous determination of syringic acid and a-asarone in human plasma was achieved successfully,even in the presence of unknown interferences.Average recoveries and figures of merit like LOD,LOQ,SEN and SEL were calculated and the results were satisfactory.The preparation of human plasma is simple due to the "second-order advantage".The satisfactory results implied the strategy has advantages of simple,sensitive and fast and can provide reliable theoretical and technical basis for clinical drug quantitative analysis and pharmacokinetics study.In Chapter 4,Flavonoids have been demonstrated to indicate a wide range of beneficial properties such as anti-inflammatory,antihypertensive,antiarrhythmic and antioxidant activity.Aurantii fructus immaturus(AFI)belongs to the families rutaceae and can be used as antioxidant,useful for treatment of obesity and have anti-carcinogenic activity.As the major active components of the medicine,flavonoids are thought to be the most important bioactive markers for the basic quality control of AFI.Therefore,an economical and simple method for simultaneous determination of flavonoids is of great importance.Most quantitative methods in literature are based on liquid chromatography with different detectors,but there are some drawbacks of time-consuming and complicated pretreatment,A novel strategy that combines the second-order calibration method based on the alternatiig trilinear decomposition(ATLD)algorithm with high performance liquid chromatography with diode-detector(HPLC-DAD)was proposed to quantify flavonoids in AFI samples from different places.This method proved to be a useful tool for handling the overlapped peaks,uncalibrated interferences and baseline drifts existing in the process of chromatographic separation,which benefited from the "second-order advantages",making the determination of six flavonoids within 8 min under a simple mobile phase condition.Experimental results indicated the proposed method was fast and simple and has broad prospects for simultaneous determination of multi-components in complex systems.In Chapter 5,Pigment is a common food additives in beverage,responsible add can improve the luster and taste of food.But excessive use will do harm to people's health.However,synthetic pigments is widely used in food processing because of its low cost,bright colors,easy dyes and stable characteristics.But synthetic pigments not only can't provide nutrition to body,but also has certain harm to people's health.Excessive intake will damage the nervous and digestive systems,etc.Therefore,determination of synthetic pigments is of great importance,to ensure that prohibited synthetic pigments is not added in the food,the allowable synthetic pigments is used within the prescribed scope.In this chapter,a chemometrics-assisted high performance liquid chromatography-diode array detection strategy was proposed for simultaneously determination of six synthetic pigments in beverage.The quantitative analysis was realized successfully in spite of in the presence of backgrounds and co-eluted peaks.And the established method was applicable for different beverage.All results indicated that the proposed method was more simple,economical and universal comparing with the conventional chromatographic methods.