Rapid isolation and identification of active antioxidant ingredients from Gongju using HPLC-DAD-ESI-MS(n) and postcolumn derivatization.

Flos Chrysanthemi (Gongju, GJ) is used to prepare a herbal tea that is commonly consumed as a health beverage in Asia and is believed to contain abundant beneficial antioxidants. To rapidly identify the chemical constituents and to obtain the profile related to antioxidant activity, an online analytical method combining high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap time-of-flight mass spectrometry (HPLC-DAD-ESI-IT-TOF-MS(n)) and postcolumn derivatization (PCD) has been applied for a precise and thorough identification of the chemical constituents. Meanwhile, the antioxidant profile has also been characterized by directly measuring the scavenging activity of each compound for the free radical produced by DPPH. As a result, 13 compounds have been identified in GJ, 7 of which account for its antioxidant activity. The established LC-MS(n)-PCD system has proved to offer a useful strategy for correlating the chemical profile with the bioactivities of the components without their isolation and purification, and may be used for multicomponent analysis of active substances in other foods and herbs.

Determination of phthalate esters in physiological saline solution by monolithic silica spin column extraction method / 药物分析学报

Monolithic silica spin column extraction （MonoSpin-SPE） was developed as a simple, sensitive, and eco-friendly pretreatment method which combined with ultra-fast liquid chromatography-mass spectrometry （UFLC-MS） to determine the levels of six phthalate esters, dimethyl- （DMP）, diethyl- （DEP）, dipropyl- [ DPrP], butyl-benzyl- （BBP）, dicyclohexyl- （DcHP）, and di-n-octyl-（DOP） phthalate in physiological saline samples. Under optimized experimental conditions, the method was linear in the following ranges： 0.2- 50 μg/L for DMP, DEP, DPrP, DcHP and DOP; 5- 100 μg/L for BBP. The correlation coefficients （R2 ） were in the range of 0. 9951 - 0. 9995 for all the analytes and the limits of detection （LODs） and limits of quantification （LOQs） were in the ranges of 0.02 - 0.9 μg/L and 0.08 - 2.7μg/L, respectively. The pretreatment process showed good reproducibility with inter-day and intra-day relative standard deviations （RSDs） below 8.5% and 11.2%, respectively. This method was used to determine the levels of six phthalate esters in physiological saline samples and the recoveries ranged from 71.2% to 107.3%. DMP and DEP were found in actual physical saline samples （brand A and brand B）.

Determination of phthalate esters in physiological saline solution by monolithic silica spin column extraction method / 药物分析学报

Monolithic silica spin column extraction (MonoSpin-SPE) was developed as a simple,sensitive,and eco-friendly pretreatment method which combined with ultra-fast liquid chromatography-mass spectrometry (UFLC-MS) to determine the levels of six phthalate esters,dimethyl-(DMP),diethyl-(DEP),dipropyl-[DPrP],butyl-benzyl-(BBP),dicyclohexyl(DcHP),and di-n-octyl-(DOP) phthalate in physiological saline samples.Under optimized experimental conditions,the method was linear in the following ranges:0.2 - 50 μg/L for DMP,DEP,DPrP,DcHP and DOP; 5- 100,μg/L for BBP.The correlation coefficients (R2 ) were in the range of 0.9951- 0.9995 for all the analytes and the limits of detection (LODs) and limits of quantification (LOQs) were in the ranges of 0.02- 0.9 μg/L and 0.08- 2.7 μg/L,respectively.The pretreatment process showed good reproducibility with inter-day and intra-day relative standard deviations (RSDs) below 8.5％ and 11.2％,respectively.This method was used to determine the levels of six phthalate esters in physiological saline samples and the recoveries ranged from 71.2％ to 107.3％.DMP and DEP were found in actual physical saline samples (brand A and brand B).