Profiling and analysis of multiple compounds in rhubarb decoction after processing by wine steaming using UHPLC–Q‐TOF‐MS coupled with multiple statistical strategies

Rhubarb is one of the most popular traditional Chinese medicines and has been used for thousands of years in many Asian countries. Prepared rhubarb is obtained by steaming raw rhubarb with glutinous rice wine until it turned black in appearance both inside and outside. After processing, the therapeutic effects of prepared rhubarb change a lot. To find out the exact compound changes of the chemical profile in a decoction of rhubarb after processing and to clarify the material basis of the changed therapeutic effects, an ultra‐high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry method coupled with automated data analysis software and statistical strategy was developed. As a result, 63 peaks in raw rhubarb and 54 peaks in prepared rhubarb were detected, and a total of 45 chemical compounds were identified. The analysis data were subjected to a principle component analysis and a t‐test. Based on the results, 16 peaks were found to be the main contributors to the significant difference (p < 0.05) between raw and prepared rhubarb. Compared with raw rhubarb, the content of 15 components in prepared rhubarb was lower, while only rhein (1,8‐dihydroxy‐3‐carboxy anthraquinone) showed a higher intensity.     

Coupling needle‐trap devices with comprehensive two‐dimensional gas chromatography with high‐resolution time‐of‐flight mass spectrometry to rapidly reveal the chemical transformation of volatile components from sulfur‐fumigated ginseng

Sulfur‐fumigation could alter the quality of white ginseng by damaging the bioactive compounds and generating sulfur‐containing materials. In the present study, coupling needle‐trap devices with comprehensive two‐dimensional gas chromatography and high‐resolution time‐of‐flight mass spectrometry was applied to rapidly reveal chemical transformation of volatile components from sulfur‐fumigated ginseng. Thirty‐two volatile compounds were not in white ginseng samples after sulfur‐fumigation. Furthermore, 20 sulfur‐containing compounds were identified for the first time in volatile oil of sulfur‐fumigated white ginseng. The established approach could be applied to discriminate sulfur‐fumigated white ginseng among commercial samples and to control the quality of white ginseng.     

Fast ultrasound‐assisted extraction combined with LC–MS/MS of perfluorinated compounds in manure

A fast analytical method for the determination of perfluorinated compounds in poultry manure by LC–MS/MS was developed. The extraction was carried out by ultrasound‐assisted extraction of 1 g of sample, during 2 × 15 min using low volume (5.5 mL) of a mixture of methanol and acetonitrile. An efficient extraction of perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl sulfonamides from poultry manure was obtained with recoveries higher than 81%. The cleanup of extracts was carried out by dispersive SPE. The validation of the proposed method showed the suitability of this procedure to determine perfluorinated compounds in poultry manure with detection limits in the range of 0.44–2.12 ng/g, depending on the target compound. In comparison with previously published methods, the miniaturization of the sample preparation method with ultrasound‐assisted extraction together with the use of a core‐shell column permit a lower consumption of organic solvents and a fast analysis of perfluorinated compounds. Manure samples obtained from Spanish commercial farms were analyzed and low perfluorinated compounds levels were found, which may be originated by dietary or environmental exposure. The highest concentrations measured corresponded to the perfluoroalkyl sulfonates, which varied from 8.2 to 35.9 ng/g.     

HPLC with quadrupole TOF‐MS and chemometrics analysis for the characterization of Folium Turpiniae from different regions

Folium Turpiniae has been used as a traditional Chinese medicine for the treatment of abscesses, fevers, gastric ulcers, and inflammations. This paper describes a strategy of combining HPLC with photodiode array detection and quadrupole TOF‐MS, as well as phytochemical and chemometrics analysis for the characterization, isolation, and simultaneous quantification of the chemical constituents of Folium Turpiniae. 19 constituents were identified, namely, 11 flavonoids, seven gallic acid derivates, and quinic acid. Among them, 15 compounds were identified in this herbal medicine for the first time; compound 10 appears to be novel and was isolated and confirmed as ellagic acid‐3‐O‐α‐l ‐rhamnopyranoside by NMR spectroscopy and MS. In addition, nine marker compounds, namely gallic acid ( 2 ), ellagic acid‐3‐O‐α‐l ‐rhamnopyranoside ( 10 ), apigenin‐7‐O‐(2′′‐rhamnosyl)gentiobioside ( 11 ), ellagic acid ( 12 ), luteolin‐7‐O‐β‐d ‐neohesperidoside ( 13 ), ligustroflavone ( 14 ), 4′‐O‐methylellagic acid‐3‐O‐α‐l ‐rhamnopyranoside ( 16 ), rhoifolin ( 17 ), and neobudofficide ( 18 ), were quantified simultaneously in ten batches of Folium Turpiniae collected from different regions. Moreover, hierarchical clustering analysis and principal component analysis indicated that both samples from Hubei ( S1 ) and Guangxi ( S3 ) provinces showed apparent differences from the others. Samples from Jiangxi province ( S2 , S4 , and S7–10 ) possessed similar properties and therefore belong to the same group.     

SPE–HPLC–MS/MS method for the trace analysis of tobacco‐specific N‐nitrosamines and 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol in rabbit plasma using tetraazacalix[2]arene[2]triazine‐modified silica as a sorbent

Tobacco‐specific N‐nitrosamines (TSNAs), including N′‐nitrosonornicotine, 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone, N′‐nitrosoanatabine, and N′‐nitrosoanabasine, have been implicated as a source of carcinogenicity in tobacco and cigarette smoke. We present a rapid and effective method comprising SPE based on tetraazacalix[2]arene[2]triazine‐modified silica as sorbent and analysis with HPLC–MS/MS for the determination of TSNAs and 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL), a metabolite of 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone, in rabbit plasma. The linear dynamic ranges were 10–2000 pg/mL for NNAL and 4–2000 pg/mL for the four TSNAs with good correlation coefficients (>0.9965). The LODs were in the range of 0.9–3.7 pg/mL, and the LOQs were between 2.9 and 12.3 pg/mL. The accuracies of the method were also evaluated and found to be in the range of 90.1–113.3%. This method is promising to be applied to the preconcentration and determination of TSNAs and NNAL in smoke and human body fluids.     

A 2‐D‐HPLC‐CE platform coupled to ESI‐TOF‐MS to characterize the phenolic fraction in olive oil

A 2‐D‐HPLC/CE method was developed to separate and characterize more in depth the phenolic fraction of olive oil samples. The method involves the use of semi‐preparative HPLC (C18 column 250×10 mm, 5 μm) as a first dimension of separation to isolate phenolic fractions from commercial extra‐virgin olive oils and CE coupled to TOF‐MS (CE‐TOF‐MS) as a second dimension, to analyze the composition of the isolated fractions. Using this method, a large number of compounds were tentatively identified, some of them by first time, based on the information concerning high mass accuracy and the isotopic pattern provided by TOF‐MS analyzer together with the chemical knowledge and the behavior of the compounds in HPLC and CE. From these results it can be concluded that 2‐D‐HPLC‐CE‐MS provides enough resolving power to separate hundreds of compounds from highly complex samples, such as olive oil. Furthermore, in this paper, the isolated phenolic fractions have been used for two specific applications: quantification of some components of extra‐virgin olive oil samples in terms of pure fractions, and in vitro studies of its anti‐carcinogenic capacity.     

Simultaneous determination of pyrifluquinazon and its main metabolite in fruits and vegetables by using QuEChERS–HPLC–MS/MS

A rapid, reliable, and sensitive method is reported for the simultaneous analysis of pyrifluquinazon and its main metabolite NNI‐0101‐1H in fruits (strawberry and cherry) and vegetables (cucumber and tomato) using high‐performance liquid chromatography coupled with tandem mass spectrometry. A modified, quick, easy, cheap, effective, rugged, and safe procedure was used for the sample pre‐preparation. The target analytes were extracted with acetonitrile and then cleaned up using dispersive solid‐phase extraction procedure with primary secondary amine. Sample analysis was performed using electrospray ionization in positive mode. Good linearities with the correlation coefficients higher than 0.9991 were obtained in the range of 1–1000 μg/L under the optimized conditions. The average recoveries of the pyrifluquinazon and NNI‐0101‐1H were in the range of 71.4–106.0% with the relative standard deviations 1.8–11.8% in all matrices at three spiked levels (10, 100, and 1000 μg/kg). The limit of quantification 10 μg/kg was set as the lowest spiked level. The developed method is reliable and effective for the routine monitoring of pyrifluquinazon and its metabolite NNI‐0101‐1H in fruits and vegetables to ensure food safety.     

Vortex‐assisted liquid–liquid microextraction for the rapid screening of short‐chain chlorinated paraffins in water

The rapid screening of trace levels of short‐chain chlorinated paraffins in various aqueous samples was performed by a simple and reliable procedure based on vortex‐assisted liquid–liquid microextraction combined with gas chromatography and electron capture negative ionization mass spectrometry. The optimal vortex‐assisted liquid–liquid microextraction conditions for 20 mL water sample were as follows: extractant 400 μL of dichloromethane; vortex extraction time of 1 min at 2500 × g; centrifugation of 3 min at 5000 × g; and no ionic strength adjustment. Under the optimum conditions, the limit of quantitation was 0.05 μg/L. Precision, as indicated by relative standard deviations, was less than 9% for both intra‐ and inter‐day analysis. Accuracy, expressed as the mean extraction recovery, was above 91%. The vortex‐assisted liquid–liquid microextraction with gas chromatography and electron capture negative ionization mass spectrometry method was successfully applied to quantitatively extract short‐chain chlorinated paraffins from samples of river water and the effluent of a wastewater treatment plant, and the concentrations ranged from 0.8 to 1.6 μg/L.     

HPLC‐Q‐TOF‐MS/MS for analysis of major chemical constituents of Yinchen–Zhizi herb pair extract

The Yinchen–Zhizi herb pair (YZHP) consists of Herba Artemisiae Scopariae (Yinchen in Chinese) and Fructus Gardeniae (Zhizi in Chinese), and is mainly used to treat icteric hepatitis, itching skin and eczema. However, the bioactive constituents responsible for the pharmacological effects of YZHP are still unclear to date. In this work, a rapid and sensitive method was established to comprehensively study the constituents in YZHP extract by HPLC‐Q‐TOF MS/MS. The analysis was performed on an HPLC system equipped with an Agilent poroshell 120 EC‐C₁₈ column (100 × 2.1 mm, 2.7 mm) working in a gradient elution program coupled to quadrupole‐time‐of‐flight mass spectrometry operating in the negative ion mode. As a result, a total of 46 compounds including 17 from Herba Artemisiae Scopariae and 36 from Fructus Gardeniae were detected and tentatively identified in YZHP extract by comparing the retention time and mass spectrometry and retrieving the reference literature. More importantly, a series of constituents, such as many iridoid glycosides, were reported for the first time in this formula. The HPLC‐Q‐TOF MS/MS method was developed and utilized successfully to identify the major constituents in YZHP extract and would be helpful for further metabolism and pharmacology research on YZHP. Copyright © 2013 John Wiley & Sons, Ltd.     

Screening anaphylactic components of MaiLuoNing injection by using rat basophilic leukemia‐2H3 cell membrane chromatography coupled with HPLC–ESI‐TOF‐MS

MaiLuoNing injection is a traditional Chinese medicine that used clinically since the 1950s in China. However, anaphylactic reactions, through the potentiation of mast cell degranulation, have been reported. In the present study, a rat basophilic leukemia‐2H3 cell membrane chromatography coupled with high‐performance liquid chromatography and electrospray ionization‐ion trap‐time of flight‐mass spectrometry method was established for screening, analyzing, and identifying the potential anaphylactic components of MaiLuoNing injection. Harpagoside, a potential degranulator of rat basophilic leukemia‐2H3 cells, was retained in rat basophilic leukemia‐2H3 cell membrane chromatography. We aimed to evaluate the retained components to determine which of those were capable of inducing degranulation of basophilic leukemia cells. A β‐hexosaminidase assay revealed that harpagoside can induce rat basophilic leukemia‐2H3 cell degranulation in a dose‐dependent manner. BLBA/c mice also exhibit passive cutaneous anaphylaxis in response to harpagoside. These results indicate that rat basophilic leukemia‐2H3 cell membrane chromatography coupled with high‐performance liquid chromatography and electrospray ionization ion trap time‐of‐flight mass spectrometry is effective in screening for the anaphylactic components of MaiLuoNing injection.     

Approach based on high‐performance liquid chromatography fingerprint coupled with multivariate statistical analysis for the quality evaluation of Gastrodia Rhizoma

Gastrodia Rhizoma is a Traditional Chinese Medicine applied in the treatment of stroke, numbness of limb, headache and dizziness. However, its clinical effect is threatened by sulfur‐fumigation used in the process of storage. This article employs content determination coupled with high‐performance liquid chromatography fingerprint to investigate the effect of sulfur‐fumigation on Gastrodia Rhizoma so as to evaluate the quality of Gastrodia Rhizoma. The result was that most active ingredient in Gastrodia Rhizoma decreased after sulfur‐fumigation and the fingerprints analyzed by mathematical statistics between sulfur‐fumigated Gastrodia Rhizoma and unfumigated Gastrodia Rhizoma have substantial differences, which reveals that sulfur‐fumigation has a significant influence on the quality of Gastrodia Rhizoma. The conclusion of hierarchical clustering analysis, principal component analysis and partial least squares could validate each other, which implies that the method of mathematical statistics applied for assessing the quality of Gastrodia Rhizoma is effective and stable. The method not only affords a viable strategy for distinguishing Gastrodia Rhizoma whether sulfur‐fumigated or not and assessment of the quality of Gastrodia Rhizoma, but also provides a reference for other herbal medicine that suffers from sulfur‐fumigation.     

Rapid identification of anti‐inflammatory compounds from Tongmai Yangxin Pills by liquid chromatography with high‐resolution mass spectrometry and chemometric analysis

We present an integrated approach to rapidly identify anti‐inflammatory compounds of TongmaiYangxin Pills (TMYXP), a botanical drug for the treatment of cardiovascular disease. Liquid chromatography coupled with high‐resolution mass spectrometry was used to analyze the chemical composition of TMYXP. Eighty compounds of TMYXP including flavonoids, coumarins, iridoid glycosides, saponins, and lignans, were identified unambiguously or tentatively. After the rapid isolation and bioassay, 18 fractions of TMYXP were obtained and their anti‐inflammatory activities were evaluated in lipopolysaccharide‐stimulated RAW 264.7 macrophages. We performed chemometric analysis to reveal the correlation between the chemical and pharmacological information of the fractions to facilitate the identification of active compounds. To verify the reliability of the proposed method in discovering active components from a complex mixture, activities of seven compounds, which were positively or negatively related to bioactivity according to calculation, were validated in vitro. Results indicated that six active compounds with high R values exerted certain anti‐inflammatory effects in a dose‐dependent manner with IC₅₀ values of 53.6–204.1 μM. Our findings suggest that the integrated use of identification based on high‐resolution mass spectrometry and chemometric methods could rapidly identify active compounds from complex mixture of natural products.     

Determination of avoparcin in animal tissues and milk using LC‐ESI‐MS/MS and tandem‐SPE

A highly sensitive and selective method using LC‐ESI‐MS/MS and tandem‐SPE was developed to detect trace amounts of avoparcin (AV) antibiotics in animal tissues and milk. Data acquisition using MS/MS was achieved by applying multiple reaction monitoring of the product ions of [M + 3H]³⁺ and the major product ions of AV‐α and ‐β at m/z 637 → 86/113/130 and m/z 649 → 86/113/130 in ESI(+) mode. The calculated instrumental LODs were 3 ng/mL. The sample preparation was described that the extraction using 5% TFA and the tandem‐SPE with an ion‐exchange (SAX) and InertSep C18‐A cartridge clean‐up enable us to determine AV in samples. Ion suppression was decreased by concentration rates of each sample solution. These SPE concentration levels could be used to detect quantities of 5 ppb (milk), 10 ppb (beef), and 25 ppb (chicken muscle and liver). The matrix matching calibration graphs obtained for both AV‐α (r >0.996) and ‐β (r >0.998) from animal tissues and milk were linear over the calibration ranges. AV recovery from samples was higher than 73.3% and the RSD was less than 12.0% (n = 5).     

Characterization and discrimination of raw and vinegar‐baked Bupleuri radix based on UHPLC‐Q‐TOF‐MS coupled with multivariate statistical analysis

Bupleuri Radix is a commonly used herb in clinic, and raw and vinegar‐baked Bupleuri Radix are both documented in the Pharmacopoeia of People's Republic of China. According to the theories of traditional Chinese medicine, Bupleuri Radix possesses different therapeutic effects before and after processing. However, the chemical mechanism of this processing is still unknown. In this study, ultra‐high‐performance liquid chromatography with quadruple time‐of‐flight mass spectrometry coupled with multivariate statistical analysis including principal component analysis and orthogonal partial least square‐discriminant analysis was developed to holistically compare the difference between raw and vinegar‐baked Bupleuri Radix for the first time. As a result, 50 peaks in raw and processed Bupleuri Radix were detected, respectively, and a total of 49 peak chemical compounds were identified. Saikosaponin a, saikosaponin d, saikosaponin b₃, saikosaponin e, saikosaponin c, saikosaponin b₂, saikosaponin b₁, 4′′‐O‐acetyl‐saikosaponin d, hyperoside and 3′,4′‐dimethoxy quercetin were explored as potential markers of raw and vinegar‐baked Bupleuri Radix. This study has been successfully applied for global analysis of raw and vinegar‐processed samples. Furthermore, the underlying hepatoprotective mechanism of Bupleuri Radix was predicted, which was related to the changes of chemical profiling.     

A purge and trap technique to capture volatile compounds combined with comprehensive two‐dimensional gas chromatography/time‐of‐flight mass spectrometry to investigate the effect of sulfur‐fumigation on Radix Angelicae Dahuricae

Sulfur‐fumigation is known to reduce volatile compounds that are the main active components in herbs used in herbal medicine. We investigated changes in chemical composition between sun‐dried and sulfur‐fumigated Radix Angelicae Dahuricae using a purge and trap technique to capture volatile compounds, and two‐dimensional gas chromatography/time‐of‐flight mass spectrometry for identification. Using sun‐dried Radix Angelicae Dahuricae samples as a reference, the results showed that 73 volatile compounds, including 12 sulfide compounds, were found to be present only in sulfur‐fumigated samples. Furthermore, 32 volatile compounds that were found in sun‐dried Radix Angelicae Dahuricae samples disappeared after sulfur‐fumigation. The proposed method can be applied to accurately discriminate sulfur‐fumigated Radix Angelicae Dahuricae from different commercial sources. Copyright © 2014 John Wiley & Sons, Ltd.     

Applications of solid‐phase micro‐extraction with mass spectrometry in pesticide analysis

Pesticides, widely applied in agriculture, can produce a variety of transformation products and their continuous use causes deleterious effects to ecosystem. Efficient and sensitive analytical techniques for enrichment and analysis of pesticides samples are highly required. Compared with other extraction methods, solid‐phase micro extraction is a solvent free, cost effective, robust, versatile, and high throughput sample preparation technique, especially for the analysis of pesticides from complicated matrices. Coupling of solid‐phase micro extraction with gas chromatography and mass spectrometry and liquid chromatography–mass spectrometry has been extensively applied in pesticide analysis. On the other hand, in recent years, combination of fast separation using solid‐phase micro extraction and rapid detection using ambient mass spectrometry is providing highly efficient pesticide screening. This article summarizes the applications of solid‐phase micro extraction coupled to mass spectrometry for pesticides analysis.     

Syringe cleanup with UHPLC–MS/MS for nitroimidazoles and steroids detection in manure‐based fertilizers

A syringe‐dispersive solid‐phase extraction method was developed for the determination of seven nitroimidazoles and nine steroids in manure‐based fertilizers by ultra‐high performance liquid chromatography with tandem mass spectrometry. Methanol and acetonitrile were used to extract the sample, and mixed dispersive sorbents dispersed in the syringe were used for purification. The extract was separated with an HSS‐T3 column and detected in positive or negative multiple reaction monitoring mode. Under the optimal conditions, the recoveries of the 16 compounds ranged from 70.3 to 112.3% at the four spiked levels (3, 10, 20, and 50 μg/kg) and the relative standard deviations ranged from 1.0 to 12.4%. The limits of detection and quantification were 0.22–0.86 and 0.73–2.87 μg/kg, respectively. This method is simple, fast, and reliable, and can be used to simultaneously screen and determine nitroimidazoles and steroids in manure‐based fertilizers.     

Simultaneous determination of 106 pesticides in nuts by LC–MS/MS using freeze‐out combined with dispersive solid‐phase extraction purification

As a result of the low water content and high fat matrices in nuts, it is very difficult to simultaneously determine multi‐pesticides in trace levels. Here, a sample pretreatment method was developed in which, microwave‐assisted solvent extraction was firstly used to extract pesticides, and then a two‐step cleanup method was conducted combining freeze‐out with dispersive solid‐phase extraction to remove the lipidic matrix. By this way, 106 pesticides were simultaneously determined in the complicated nut sample by using an ultra‐high pressure liquid chromatography coupled with a tandem mass spectrometer. Average recoveries were 75.3–119.3% with relative standard deviations < 14% at three concentration levels. The limits of detection and quantification were in the ranges of 0.3–3.0 and 1.0–10.0 μg/kg, respectively. Furthermore, the method was successfully applied to the determination of pesticides in 180 commercial nut samples.     

Simultaneous analysis by Quadrupole‐Orbitrap mass spectrometry and UHPLC‐MS/MS for the determination of sedative‐hypnotics and sleep inducers in adulterated products

Adulterated products are continuously detected in society and cause problems. In this study, we developed and validated a method for determining synthetic sedative‐hypnotics and sleep inducers, including barbital, benzodiazepam, zolpidem, and first‐generation antihistamines, in adulterated products using Quadrupole‐Orbitrap mass spectrometry and ultrahigh performance liquid chromatography with tandem mass spectrometry. In Quadrupole‐Orbitrap mass spectrometry analysis, target compounds were confirmed using a combination of retention time, mass tolerance, mass accuracy, and fragment ions. For quantification, several validation parameters were employed using ultrahigh performance liquid chromatography with tandem mass spectrometry. The limit of detection and limit of quantitation was 0.05–53 and 0.17–177 ng/mL, respectively. The correlation coefficient for linearity was more than 0.995. The intra‐ and interassay accuracies were 86–110 and 84–111%, respectively. Their precision values were evaluated as within 4.0 (intraday) and 10.7% (interday). Mean recoveries of target compounds in adulterated products ranged from 85 to 116%. The relative standard deviation of stability was less than 10.7% at 4°C for 48 h. The 144 adulterated products obtained over 3 years (2014–2016) from online and in‐person vendors were tested using established methods. After rapidly screening with Quadrupole‐Orbitrap mass spectrometry, the detected samples were quantified using ultrahigh performance liquid chromatography with tandem mass spectrometry. Two of them were adulterated with phenobarbital.     

Simultaneous determination of pyrametostrobin and its two metabolites in cucumber and soil using a quick,easy, cheap,effective, rugged,and safe method with HPLC–MS/MS

An easy, effective and sensitive analytical method for the simultaneous determination of a novel fungicide pyrametostrobin and its two metabolites pyrametostrobin‐M1 and pyrametostrobin‐M2 in cucumber and soil was developed using a quick, easy, cheap, effective, rugged, and safe method with high‐performance liquid chromatography and tandem mass spectrometry. The extraction solvent was acetonitrile, and cleanup sorbents were primary secondary amine and graphitized carbon black for cucumber samples and primary secondary amine for soil samples. The three target compounds were successfully separated between 3.2 and 3.9 min using a Waters CORTECS™ C₁₈ column connected to an electrospray ionization source. All the matrix‐matched samples at three fortified levels (10, 100 and 1000  μg/kg) provided satisfactory recoveries in the range of 78.8–93.8% with relative standard deviations below 6.9%. The limits of quantitation for the three compounds were below 0.183 μg/kg. The proposed method was validated by analyzing real samples.