Traceability Research on Based on SWATHtoMRM.

SWATHtoMRM technology was used in this experiment to further identify and trace the sources of and produced in the same area using TOF and MS-MRM. After the conversion of the R package of SWATHtoMRM, 191 MRM pairs of positive ions and 96 pairs of negative ions were obtained. and can be separated very well using the PCA and PLS-DA analysis of MRM ion pairs; this shows that there are obvious differences in chemical composition between and , which clearly proves that the pseudotargeted metabolomics method based on SWATHtoMRM can be used for traceability identification research.

Determination of new generation amide insecticide residues in complex matrix agricultural food by ultrahigh performance liquid chromatography tandem mass spectrometry.

Eight new generation amide insecticide residues analysis by multiwalled carbon nanotubes (MWCNs) cleanup, combined with QuEChERS and ultrahigh performance liquid chromatography tandem mass spectrometry has been developed and successfully applied in complex matrix such as orange, celery, onion, litchi, mango, shallot, chives, avocado, garlic. The matric effect of MWCNs is optimized and compared with ordinary cleanup materials. The results show that the performance of MWCNs is fine and effectively reduce matrix interference.

The level variation of N-(carboxymethyl)lysine is correlated with chlorogenic acids in Arabica L. Coffee beans under different process conditions.

N-(carboxymethyl) lysine (CML) is universally used as a marker of the occurrence of advanced glycation end products (AGEs) in foods. This study investigated the level changes of CML, chlorogenic acids (CQAs), lysine (Lys), fat and pH in coffee during roasting. The CML level went up slowly in the first 10 mins, then declined sharply during the next 2 mins, and kept increasing constantly in the following baking time, while the lowest CML level was obtained by roasting at 235 °C for 12 mins.

[Rapid determination of multiple prohibited and restricted veterinary drug residues in fish and shrimp by ultra high performance liquid chromatography-tandem mass spectrometry].

A method was established for the rapid determination of 28 prohibited and restricted veterinary drugs of five classes (sulfonamides, quinolones, chloramphenicols, nitrofurans metabolites and triphenylmethane) in fish and shrimp by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) coupled with simultaneous extraction and purification. After optimizing the sample pretreatment methods and chromatographic conditions, the samples were hydrolyzed with hydrochloric acid. The five kinds of residual drugs were simultaneously extracted with acetonitrile after nitrofuran metabolites derivatized with 2-nitrobenzaldehyde.

[Simultaneous determination of antibiotics and triphenylmethanes veterinary drug residues in fish and shrimp by dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry].

A method was established to rapidly determine 20 kinds of veterinary drug residues including three catagories of antibiotics (sulfonamides, quinolones, and chloramphenicols) and two kinds of triphenylmethanes (malachite green (MG) and leucomalachite green (LMG)) in fish and shrimp, based on dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry. The samples were first hydrolyzed using a dipotassium hydrogen phosphate solution, and then extracted using acetonitrile. Afterward, the extraction solution was dehydrated and salted out with sodium chloride and condensed to nearly dry using a rotating evaporator.

Determination of Enantiomeric Excess by Solid-Phase Extraction Using a Chiral Metal-Organic Framework as Sorbent.

Metal-organic frameworks (MOFs) have recently attracted considerable attention because of their fascinating structures and intriguing potential applications in diverse areas. In this study, we developed a novel method for determination of enantiomeric excess () of (±)-1,1'-bi-2-naphthol by solid-phase extraction (SPE) using a chiral MOF, [Co(l-tyr)](l-tyrCo), as sorbent. After optimization of the experimental conditions, a good linear relationship between the and the absorbance of the eluate (² = 0.

[Determination of six amide herbicide residues in soil by QuEChERS-gas chromatography-mass spectrometry].

A method was developed for the determination of six amide herbicides, such as acetochlor, alachlor, metolachlor, metazachlor, butachlor and pretilachlor, by QuEChERS-gas chromatography-mass spectrometry. The soil samples were extracted by 10 mL acetonitrile, 10 mL deionized water and 4 g sodium chloride, then purified with 50 mg -propyl ethylenediamine (PSA), 50 mg C18, 10 mg graphitized carbon black (GCB) and 100 mg MgSO. Low-polar silica capillary column HP-5MS was used.

[Determination of amantadine and rimantadine residues in egg and chicken samples by dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry].

A method was developed for the determination of residual amantadine and rimantadine in eggs and chickens by dispersive solid phase extraction-ultra high performance liquid chromatography-tandem mass spectrometry. Egg and chicken samples were extracted with ammonia water-acetonitrile (2:98, v/v). The extraction solution was dried to 1 mL under nitrogen, and then purified by dispersive solid phase extraction method with C18 and NH2 sorbents.

A 3D Homochiral MOF [Cd2(d-cam)3]•2Hdma•4dma for HPLC Chromatographic Enantioseparation.

Up to now, some chiral metal-organic frameworks (MOFs) have been reported for enantioseparation in liquid chromatography. Here we report a homochiral MOF, [Cd2(d-cam)3]·2Hdma·4dma, used as a new chiral stationary phase for high-performance liquid chromatographic enantioseparation. Nine racemates of alcohol, naphthol, ketone, and base compounds were used as analytes for evaluating the separation properties of the chiral MOF packed column.

[Determination of 41 pesticide residues in vegetables by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry].

A multiresidue analytical method for the rapid determination of 41 pesticide residues in vegetables was developed by using QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), including recessive pesticides, banned pesticides and pesticides with restrict use, plant growth regulators and some other pesticides with high detection rates. The vegetable sample was extracted by 1% (v/v) acetic acid-acetonitrile, cleaned-up by primary secondary amine (PSA) and injected for analysis. The positive and negative ion modes and multiple reaction monitoring (MRM) mode were used in the analysis, and the analytes were quantified by the external standard method.

Chiral recognition of a 3D chiral nanoporous metal-organic framework.

Some racemates including alcohol, ketone, flavone, phenol, base, and amide racemates etc. were successfully separated by using a 3D chiral nanoporous metal-organic framework (MOF) as a new chiral stationary phase in HPLC. The experimental results show that the chiral MOF possesses excellent recognition ability for various racemates, and indicate that enantioseparation on the chiral MOF column is practicable.