Materials and methods To analyze the catalytic activity of PHGDH on possible alternative substrates, we conducted in vitro biochemical assays on recombinant human PHGDH. The reaction rate in the reductive direction with various substrates was monitored based on NADH consumption, measured by absorbance at 340 nm. The identity and chirality of products were analyzed by liquid chromatography-mass ...

A method for the determination of 42 hazard residues required by 'Japan Positive List System' in bottled water was described. Hazard compounds in bottled water were extracted with a solid phase extraction step using C18 disks. Determination was carried out by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). The disk extraction has high ...

Within the perspective of current and future space missions, detection separation building blocks such as amino acids are important subjects which becoming fundamental in search for origin life traces solar system. In this work, we have developed optimized a strategy adapted to experimentation detect presence acid-like compounds using gas chromatography coupled mass spectrometry (GC-MS). Select...

A method for the quantitative determination of dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP), dioctyl terephthalate (DOTP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP) in medical infusion sets was developed and validated using gas chromatography coupled with triple quadrup...

Acetylation with acetic anhydride, under both aqueous and anhydrous conditions, has been utilized to derivatize various biogenic amines and psychotropic drugs for subsequent analysis by gas chromatography (GC) or gas chromatography-mass spectrometry (GC-MS). Under basic aqueous conditions, acetic anhydride derivatizes phenols and amines but not alcohols; under anhydrous conditions, all three fu...

Fatty acids in 42 types of saponified vegetable and animal oils were analyzed by electrospray ionization mass spectrometry (ESI-MS) for the development of their rapid discrimination. The compositions were compared with those analyzed by gas chromatography-mass spectrometry (GC-MS), a more conventional method used in the discrimination of fats and oils. Fatty acids extracted with 2-propanol were...

Although gas chromatography/mass spectrometry (GS/MS) is recognized as the definitive procedure for confirming positive immunoassay screening results of urine for drugs of abuse, targeted GC/MS analysis does have limitations. False negative results can occur when interfering drugs are present at high relative concentrations. If an interfering drug competes with the targeted drug for the derivat...

This study analysed 22 strawberry and soil samples after their collection over the course of 2 years to compare the residue profiles from organic farming with integrated pest management practices in Portugal. For sample preparation, we used the citrate-buffered version of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. We applied three different methods for analysis: (1) ...

Summary Stable isotope directed metabolomics is increasingly being used to measure metabolic fluxes in microbial, plant and animal cells. Incorporation of 13C/15N isotopes into a wide range of metabolites is typically determined using gas chromatography-mass spectrometry (GC/MS) or other hyphenated mass spectrometry approaches. The DExSI pipeline is an interactive graphical software package whi...