Geographical origin traceability of rice using a FTIR-based metabolomics approach.

Infrared spectroscopy is a crucial tool to achieve the origin traceability of rice, but it is constrained by data mining. In this study, a novel infrared spectroscopy-based metabolomics analytical method was proposed to discriminate rice products from 14 Chinese cities by seeking 'wave number markers'. Principal component analysis (PCA), cluster analysis and orthogonal partial least squares discriminant analysis (OPLS-DA) were employed to separate all rice groups.

Metabolomics Approach on Non-Targeted Screening of 50 PPCPs in Lettuce and Maize.

The metabolomics approach has proved to be promising in achieving non-targeted screening for those unknown and unexpected (U&U) contaminants in foods, but data analysis is often the bottleneck of the approach. In this study, a novel metabolomics analytical method via seeking marker compounds in 50 pharmaceutical and personal care products (PPCPs) as U&U contaminants spiked into lettuce and maize matrices was developed, based on ultrahigh-performance liquid chromatography-tandem mass spectrometer (UHPLC-MS/MS) output results. Three concentration groups (20, 50 and 100 ng mL) to simulate the control and experimental groups applied in the traditional metabolomics analysis were designed to discover marker compounds, for which multivariate and univariate analysis were adopted.

[Analysis of 29 fentanyl analogs and their fragmentation mechanism by liquid chromatography-quadrupole time-of-flight mass spectrometry].

Given the wide variety of fentanyl analogs, the test for this entire group tends to be crucial and particularly difficult since all fentanyl-like substances are listed as controlled substances in China. This study meticulously analyzed the fragmentation pathways and mechanisms of 29 fentanyl analogs and summarized the fragmentation pathways and features for the entire group of fentanyl analogs, thus providing a reference for related screening tests. Fentanyl, thiofentanyl, and sufentanil were selected as the representative compounds in this study, and the fragmentation mechanism of their fragment ions was interpreted.

Metabolomics-based non-targeted screening analysis of 34 PPCPs in bovine and piscine muscles.

The metabolomics-based analytical strategy has showed superiority on the non-targeted screening of contaminants, especially for unknown and unexpected (U&U) contaminants in the field of food safety, but data analysis is often the bottleneck of the strategy. In this study, a novel metabolomics-based analytical method searching for marker compounds was developed on the basis of ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) results to accurately, rapidly and comprehensively achieve the non-targeted screening of 34 pharmaceutical and personal care products (PPCPs) as U&U contaminants spiked in bovine and piscine muscle matrices. Three concentration groups (20, 50 and 100 ng mL) were intentionally designed to simulate the control and experimental groups for the discovery of marker compounds, for which multivariate and univariate analyses were adopted.

Quantum chemical prediction of effects of temperature on hydrolysis rate of penicillin under weakly acidic condition.

Temperature and pH are important factors affecting the hydrolysis of β-lactam antibiotics in water environments. However, the determination of hydrolysis kinetics and pathways is experimentally challenging, particularly in low temperature aqueous solutions because of time and cost constraints. In this study, an equation was employed to correct the Gibbs energy calculated in aqueous solutions by density functional theory methods to predict the effect of temperature on the hydrolysis kinetics and pathways of penicillin G.

Metabolomics-based screening analysis of PPCPs in water pretreated with five different SPE columns.

The selection of solid phase extraction (SPE) columns in the pretreatment process plays a decisive role in the screening and quantification of pharmaceutical and personal care products (PPCPs). As growing PPCPs have frequently been detected in the aquatic environment, it is a burdensome task through one-by-one recovery comparison to judge which column presents relatively ideal pretreatment results for PPCPs. In view of this, we developed a novel metabolomics-based screening method based on ultrahigh-performance liquid chromatography-tandem mass spectrometer (UHPLC-MS/MS) results to accurately, rapidly and comprehensively choose a suitable column from 5 different kinds to handle 64 PPCPs in two water environments (50 μg L/pH ≅ 7.