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Two-dimensional gas chromatography (2D GC)���quadrupole time-of-flight mass spectrometry (QTOFMS) combined with derivatization was applied to determine naphthenic acids (NAs) in oil sand processed water (OSPW). Using the excellent resolution of 2D GC and mass resolution of QTOFMS with derivatization, 8 cyclohexane carboxylic acid isomers, 18 methylcyclohexyl carboxylic acid isomers, and 18 methylcyclohexyl acetic acid isomers were identified. Linear relationships across wide concentration ranges were established with correlation coefficients (R2) of 0.9995, 0.9992, and 0.9990, for cyclohexanecarboxylic acid, 4-methylcyclohexanecarboxylic acid, and 4-methylcyclohexane acetic acid. The precision, expressed as the relative standard deviation (RSD, n = 5), was from 7. 7���9.5% with recoveries between 72.0% and 84.9%. This method was applied to analyze sewage and showed high concentrations of naphthenic acids in untreated samples.

The Rosa chinensis cultivars Rosa Lvye, Rosa Knock out, Rosa Parade and Slater’scrimson China were analyzed for the volatile chemical composition in their flower petals. Headspace solid phase micro...

Twenty-six key odourants were found in Hongxin and Shatian pomelo peel oils using aroma extraction dilution analysis (AEDA). trans-2-Dodecenal was identified to be the most potent key odourant, wit...

Gynostemma pentaphyllum has gained increasing interest in recent years for its widespread use as a medicinal plant, dietary supplement, herbal tea, and vegetable in China. This herb possesses many ...

Schizonepetae Spica (SS), a well-known traditional Chinese medicine has been widely used over thousands of years. In modern medicine, it has been adopted in the traditional prescription for cancer ...

Pesticides are used to increase crop yields and preserve quality by protecting crops against pests; however, their overuse can adversely affect human health and the environment. Herein, we report the development of a multi-pesticide screening method using optimized QuEChERS coupled with liquid chromatography/quadrupole time-of-flight (QTOF) mass spectrometry for the analysis of 13 pesticides in wheat flour. Mass accuracies with errors of less than 2.4 ppm were obtained for all analysed pesticides, and the method provided satisfactory recovery and linearity. Repeatabilities of 0.3-12.7% and reproducibilities of 2.5-15.2% were observed in full-scan TOF mode. The performance of the developed full-scan TOF method was compared to that obtained in high-resolution multiple reaction monitoring (MRM-HR) mode. The limits of quantification for the full-scan TOF and MRM-HR modes ranged from 2 to 10, and 3 to 9 μg kg

Phlebodium decumanum (P. decumanum), together with other tropical ferns commonly known as Calaguala, have been empirically applied since ancient times to ameliorate inflammatory disorders, skins diseases and even cancer. There are evidences of antineoplastic potential and anti-inflammatory, immunomodulatory and antioxidant properties of the extract. Preliminary studies have also shown direct antitumor activity of the extracts. In the present article, the phytochemical composition of a hydro-ethanolic extract of P. decumanum is investigated using high-performance liquid chromatography (HPLC) with ultraviolet–visible (UV–vis) diode array detection (DAD) and electrospray ionization (ESI) quadrupole time-of-flight tandem mass spectrometry (QTOF–MS/MS) detection. First, the chromatographic profile is established as a representative fingerprint of the compounds extracted from the fern. Then, a total of 122 chemicals, including 23 flavonoids, 47 phenolic acids (34 hydroxycinnamic acids and 13 hydroxybenz...

A screening method for multiple classes of pesticides and pharmaceuticals from fish cultivation water was established using liquid chromatography coupled to quadrupole time-of-flight mass spectrome...

Rice bean (Vigna umbellata) is consumed as a common vegetable in Southeast Asia. Methyl jasmonate (MeJA) functions as an endogenous/exogenous stress signal to elicit the production of specific metabolites during sprouting. To elucidate the changes in metabolites and the effects of MeJA on rice bean sprouting, non-targeted ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry along with principal component analysis and supervised orthogonal projection to latent structure-discriminant analysis was performed to analyze the dissimilar profiles among the sprouts at different stages. Analysis of the abundance of biomarkers, such as sugars, free fatty acids, amino acids, flavonoids, benzoic acid derivatives, triglycerides, and lipids, showed the main effects of MeJA involved in the significant metabolite pathways. Our study elucidated the changes in rice bean composition and metabolites associated with various stages of sprouting and the roles of MeJA in sprout physiology. Our results can help improve this economically important grain crop.

Chinese tonic liquor is an important dietary supplement in daily use, but it often happens that illicitly adulterated drugs in Chinese tonic liquor could lead to food safety issues. In this survey, an analytical method consisting of a liquid chromatography-quadrupole-time of flight mass spectrometer (LC-Q-TOF-MS), coupled with quick easy cheap effective rugged safe (QuEChERS) pretreatment, was established for identification of phosphodiesterase type 5 enzyme (PDE-5) inhibitors in Chinese tonic liquors. 86 PDE-5 inhibitors were qualitatively analysed by employing information dependent acquisition mass spectrometry (IDA-MS) in comparison with the accurate mass of the protonated molecular ion, isotopic pattern, library and chemical formula. This method was used to test 28 Chinese tonic liquor samples. The results revealed that the IDA-MS screening method is suitable for qualitative analysis of 86 PDE-5 inhibitors. Four samples were found to be adulterated with sildenafil, tadalafil, vardenafil, isopiperazinoafil, nortadalafil and desmethylsidenafil, which was 14.3% of the tested samples.

Ultrahigh-performance liquid chromatography–quadrupole-time of-flight mass spectrometry (UHPLC–Q-TOF-MS) was widely used in identification of complex ingredients in traditional Chinese herbs and herbal medicinal preparations for its excellent performance. Yangxinshi tablet, a Chinese compound herbal medicinal formula, has excellent efficacy for the clinical treatment of cardiovascular diseases, but its active ingredients are unclear. In this study, a rapid and sensitive UHPLC–Q-TOF/MS and secondary mass spectrometry (MS2) method were developed to characterize the comprehensive ingredients in Yangxinshi tablet and rat plasma after drug administration. And finally a total of 178 constituents in the Yangxinshi tablet were identified effectively, and 39 parent molecules in rat plasma were rapidly characterized by matching the Yangxinshi tablet chemical library established by ourselves. Of which, seven groups of isomers were further distinguished according to their MS2 spectra and fragmentation ions. F...

Human intestinal microbiota comprise a complex biological system with considerable metabolic activity. Various studies have focused on the bioconversion of flavonoids. However, in addition to flavonoids, bioactive components such as iridoids also exist in many natural and traditional Chinese medicines. Little is known about the interactions of the iridoids with bacteria. Loganin, one of the main effective iridoids in the valuable traditional Chinese herbal medicine Cornus officinalis, exhibits various pharmacological activities and biological effects. Human intestinal bacteria were isolated and the conversion capability of loganin was investigated. The metabolites were determined by ultra-high performance liquid chromatography–quadrupole time-of-flight mass spectrometry. Loganin was metabolized to hydrogenated and hydroxylated loganin sulfate, acetylated loganin, loganetin, methylated loganetin, hydrogenated, and hydroxylated loganetin. The metabolic routes and metabolites of loganin were reported for the...

An ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC Q-TOF MS) metabonomics approach was employed to study the serum metabolic profiling of adenine-induced chronic renal failure (CRF) rats. Acquired data were subjected to principal component analysis (PCA) for differentiating the CRF and the normal control groups. Potential biomarkers were screened by using S-plot and were identified by the accurate mass, isotopic pattern and MS/MS fragments information obtained from UPLC Q-TOF MS analysis. Significant differences in the serum level of creatinine, amino acids and LysoPCs were observed, indicating the perturbations of amino acid metabolism and phospholipid metabolism in adenine-induced CRF rats. This research proved that metabonomics is a promising tool for disease research.

Milk thistle (Silybum marianum) is a medicinal plant commonly used as a food supplement for liver protection against hepatitis C virus. The fruits are very rich in lipids (>30%); however, their chemical structures are not well characterized. In this investigation, dry fruits were extracted using CO2 supercritical fluid extraction to obtain the crude lipid components. Triacylglycerols (TAGs) were isolated from the crude lipid extract using high-performance thin layer chromatography. Fatty acid composition of the purified TAGs was identified as their fatty acids methyl esters (FAMES) using gas chromatography mass spectrometry. Regioisomers of TAGs and their relative abundances were determined using accurate mass ultra-high-performance liquid chromatography quadrupole time of flight mass spectrometry both in the full scan and in MSMS electrospray ionization modes. Major identified fatty acids were 18:2, 18:1 and 16:0. Twenty-six different TAGs were identified with LLL, OLL, PLL, LOO and PLO as the major components.

This paper describes the use of a time-of-flight mass spectrometer as the second stage of a MS/MS instrument. This system has been improved by the addition of a newly designed data acquisition system. The performance of this instrument will be discussed along with other modifications that are in progress to give further improvements.