► UHPLC assisted by liquid–liquid partition and a comprehensive 2D-LC were developed. ► Identification of more than 100 compounds was obtained. ► Novel flavonol glycosides and several saponin isomers were described. Green and black teas ( Camellia sinensis) contain compounds ranging from simple phenolics to complex glycosides, many of which have well-recognized health benefits. Here, we describe two methodologies aiming to achieve a comprehensive analysis of hydro-alcoholic extracts of C. sinensis. In the first step, the extracts were partitioned in water, n-butanol, ethyl acetate and chloroform to separate the compounds according to their polarity, yielding less complex samples to be analyzed by ultra high performance liquid chromatography coupled with mass spectrometry (UHPLC–MS). Additionally, a comprehensive two dimensional liquid chromatography (2D-LC) technique, employing size exclusion chromatography (SEC) × reversed phase (BEH-C18) was developed. The following compounds were identified on the basis of retention time, UV-spectra and MS fragmentation patterns: catechins, theaflavins and their gallate derivatives; kaempferol, quercetin and myricetin mono-, di-, tri- and tetraglycosides; esters of quinic acid and gallic or hydroxycinnamic acids; purine alkaloids, such as caffeine and theobromine and many lipids. Additionally, there were many novel compounds that were previously undescribed, such as saponin isomers and gallic acid esters of four glycosides of myricetin, quercetin and kaempferol.
•Simultaneous HPLC analysis of sodium iron/sodium copper chlorophyllins (SIC/SCC).•Inertsil ODS-2 column and methanol/water/acetic acid mobile phase used in HPLC.•Detection performed at wavelength of 395 nm.•Main components were Fe-isochlorine e4 (for SIC) and Cu-isochlorine e4 (for SCC). A simultaneous method for analyzing sodium iron chlorophyllin (SIC) and sodium copper chlorophyllin (SCC) using high-performance liquid chromatography was developed. This method employed an Inertsil ODS-2 column and diode array detection at 395 nm, using methanol–water (97:3 and 80:20, v/v) containing 1% acetic acid as the mobile phase. Liquid chromatography–tandem mass spectrometry was used to identify the main components of SIC and SCC as Fe-isochlorine e4 and Cu-isochlorine e4, respectively. The limits of detection and quantitation of SIC were 1.2 and 4.1 mg/kg, respectively, while those of SCC were 1.4 and 4.8 mg/kg, respectively. For intraday and interday tests, the SIC recoveries from candy ranged from 81% to 101%, while SCC recoveries ranged from 100% to 109%. The developed method can be applied to the rapid determination of SIC and SCC in candy.
•Retention model in HPLC at −196°C is proposed by adsorption exchange and pseudo partition.•The proposed equation agrees well with the experimental results.•Adsorptive retention is reduced effectively using highly adsorptive additives.•Pseudo partitive retention is reduced effectively using high solubility mobile phases.•Combination of stationary and mobile phases will control the k of various analytes. Recently, we have developed ultralow-temperature high-performance liquid chromatography (HPLC) at −196°C using liquid nitrogen-based mobile phases. In this study, a retention model for ultralow-temperature HPLC, in which adsorption exchange and “pseudo partition” modes are combined, is proposed to describe the effect of the mobile phase composition on the retention of analytes. The experimental results agreed well with the equation of the proposed model. It was revealed that, in the low and high additive concentration regions, adsorption exchange and pseudo partition retention, respectively, dominate the analyte retention. The difference in the retention behavior between bare-silica and octadecylsilyl-modified silica (ODS) columns was also studied. Retention of alkanes in the ODS column was greater than that in the bare-silica one. Addition of both ethane and ethylene to the mobile phase in the ODS column afforded the elution of propylene, which was not eluted with the bare-silica column at −196°C.
•M-β-CD/ATP was prepared by modifying ATP with β-CD and ferroferric oxide.•M-β-CD/ATP and IL joint up to purify water samples and extract four fungicides.•Extractions were optimized by factor-at-a-time way and an orthogonal design.•Environmental samples were fast and efficiently extracted without centrifugation. A novel microextraction technique combining magnetic solid-phase microextraction (MSPME) with ionic liquid dispersive liquid–liquid microextraction (IL-DLLME) to determine four fungicides is presented in this work for the first time. The main factors affecting the extraction efficiency were optimized by the one-factor-at-a-time approach and the impacts of these factors were studied by an orthogonal design. Without tedious clean-up procedure, analytes were extracted from the sample to the adsorbent and organic solvent and then desorbed in acetonitrile prior to chromatographic analysis. Under the optimum conditions, good linearity and high enrichment factors were obtained for all analytes, with correlation coefficients ranging from 0.9998 to 1.0000 and enrichment factors ranging 135 and 159 folds. The recoveries for proposed approach were between 98% and 115%, the limits of detection were between 0.02 and 0.04μgL−1 and the RSDs changed from 2.96 to 4.16. The method was successfully applied in the analysis of four fungicides (azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin) in environmental water samples. The recoveries for the real water samples ranged between 81% and 109%. The procedure proved to be a time-saving, environmentally friendly, and efficient analytical technique.
•Matrix solid phase dispersion is an effective method to extract water soluble components.•UPLC–Q–TOF–MS technique was used to identify all the compounds of the extract.•MSPD–LC–MS technique could be used to control the quality of Chinese herbal medicines. A simple and low-cost method based on matrix solid-phase dispersion (MSPD) extraction, HPLC separation, diode array detection and UPLC–Q–TOF–MS have been developed for the determination of Hydroxysafflor yellow A (HSYA), Kaempferol and other main compounds in Carthamus tinctorius. The experimental parameters that may affect the MSPD method, including dispersing sorbent, ratio of dispersing sorbent to sample, elution solvent, and volume of the elution solvent were examined and optimized. The optimized conditions were determined to be that silica gel was used as dispersing sorbent, the ratio of silica gel to sample mass was selected to be 3:1, and 10mL of methanol: water (1:3, v:v) was used as elution solvent. The highest extraction yields of the two compounds were obtained under the optimized conditions. The method showed good linearity (r2≥0.999 2) and precision (RSD≤3.4%) for HSYA and Kaempferol, with the limits of detection of 35.2 and 14.5ngmL−1, respectively. The recoveries were in the range of 92.62–101.7% with RSD values ranging from 1.5 to 3.5%. At the meanwhile, there were 21 compounds in the extraction by MSPD method were identified by TOF–MS method to improve the quality control for safflower. Comparing to ultrasonic and soxhlet methods, the proposed MSPD procedure was more convenient and less time-consuming with reduced requirements on sample and solvent amounts. The proposed procedure was applied to analyze four real samples that were collected from different localities.
Objectives Non-adherence to therapy is an important cause of suboptimal blood pressure control but few practical tools exist to accurately and routinely detect it. We used a simple urine-based assay to evaluate the prevalence of antihypertensive treatment non-adherence and its impact on blood pressure in a specialist hypertension centre. Methods 208 hypertensive patients (125 new referrals, 66 follow-up patients with inadequate blood pressure control and 17 renal denervation referrals) underwent assessment of antihypertensive drug intake using high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis at the time of clinical appointment. A total of 40 most commonly prescribed antihypertensive medications (or their metabolites) were screened for in spot urine samples. Results Overall, 25% of patients were totally or partially non-adherent to antihypertensive treatment (total non-adherence 10.1%, partial non-adherence 14.9%). The highest prevalence of partial and total non-adherence was among follow-up patients with inadequate blood pressure control (28.8%) and those referred for consideration of renal denervation (23.5%), respectively. There was a linear relationship between blood pressure and the numerical difference in detected/prescribed antihypertensive medications—every unit increase in this difference was associated with 3.0 (1.1) mm Hg, 3.1 (0.7) mm Hg and 1.9 (0.7) mm Hg increase in adjusted clinic systolic blood pressure, clinic diastolic blood pressure (DBP) and 24 h mean daytime DBP (p=0.0051, p=8.62×10−6, p=0.0057), respectively. Conclusions Non-adherence to blood pressure lowering therapy is common, particularly in patients with suboptimal blood pressure control and those referred for renal denervation. HP LC-MS/MS urine analysis could be used to exclude non-adherence and better stratify further investigations and intervention.