Trace the origin of yak meat in Xizang based on stable isotope combined with multivariate statistics.

In this study, the feasibility of tracing the origin of yak meat in Xizang Autonomous Region based on stable isotope combined with multivariable statistics was researched. The δC, δN, δH and δO in yak meat were determined by stable isotope ratio mass spectrometry, and the data were analyzed by analysis of variance, fisher discriminant analysis (FDA), back propagation (BP) neural network and orthogonal partial least squares discrimination analysis (OPLS-DA). The results showed that the δC, δN, δH and δO had significant differences among different origins (P < 0.

Comprehensive analysis of different types of ginsenosides in the different parts of American ginseng by targeted and nontargeted MS/MS scanning.

To comprehensively study the ginsenosides distribution in the various tissues of American ginseng, the qualitative and quantitative-targeted and nontargeted mass spectroscopic methods were established using the high-performance liquid chromatography coupled with Qtrap triple quadrupole mass spectrometry (HPLC-QtrapQQQ-MS). The total ginsenosides of the root, stem, and leaf of American ginseng were determined by a colorimetric method, and the contents showed the order from high to low root, stem, and leaf. Eighty-two kinds of ginsenosides were detected in the different parts of American ginseng by enhanced mass scan-information-dependent data acquisition (IDA)-enhanced product ion (EPI) scan mode, including 69 from the root, 62 from the stem, and 48 from the leaf.

[Determination of prometryne residue in shellfish by gas chromatography].

Objective: To develop a method of gas chromatography (GC) for determining residues of promtryne in shellfish.

Methods: The sample was extracted with ethyl acetate, and cleaned-up with Envi-Carb SPE cartridge, alumina-N SPE cartridge, and determined by GC-FPD with DB - 1701 capillary chromatographic column (30 m x0.53 .