Track topics on Twitter Track topics that are important to you
The use of supplements for weight loss and in sports as pre-workout (ergogenic) products is widespread. Many of these supplements were found to contain active components, which were not claimed on the products labels. A validated liquid chromatography high-resolution mass spectrometry quadrupole time-of-flight (LC-QToF-MS) method was developed for the simultaneous analysis of 111 amine-based compounds belonging to ergogenics, anorectics and other active components including phenethylamines (amphetamines, ephedrines), sibutramine or yohimbine. This method involves the detection of [M+H] ions and the separation was achieved using a C column, water/acetonitrile gradient as the mobile phase. The method was validated for linearity, repeatability, accuracy, stability, system suitability, limits of quantification (LOQ) and limits of detection (LOD). The limits of detection were in the range from 0.001-0.5 μg/mL. The validated method was applied to the analysis of twenty-seven weight loss and ergogenic dietary supplements. Two-thirds of the supplements contained compounds that were not listed on the product's label. These include several phenethylamines (PEA) such as demelverine, hordenine, N, N-dimethyl-phenethylamine, synephrine, N-methyl-β-phenethylamine, and methylsynephrine. In addition, the PEA mimics such as dimethylamylamine, dimethylbutylamine other stimulants including fursultiamine, evodiamine, phenibut and theophylline were also observed. One or more of the ingredients listed on the labels were not detected in forty-four percent of the products analyzed. Positive identification was based on retention time, accurate mass and fragment ions in comparison with the respective reference standards. Development of such methods is anticipated to be of aid to regulatory agencies for the identification of undeclared exogenous components that are found in many dietary supplement products.
This article was published in the following journal.
Name: Journal of pharmaceutical and biomedical analysis
The flowers of Juglans regia L. have demonstrated their medicinal value as a part of edible plants. In this study, an analytical methodology for identification of flavonoid chemical constituents in fl...
Hongjingtian injection is made from Rhodiola wallichiana and used in the treatment of stable angina pectoris associated with coronary heart disease. In this study, the chemical constituents in Hongjin...
This work proposes a simple method for the simultaneous determination of two antidiabetic compounds, metformin and glimepiride, by ultra-high performance liquid chromatography using quadrupole time of...
Identification of the impurity in auramine O by high performance liquid chromatography-ion trap-time of flight mass spectrometry and preparation of the auramine O reference standard by preparative high performance liquid chromatography.
A novel and effective method was established for the qualitative analysis of impurities in auramine O samples of illegal food additives using high performance liquid chromatography-ion trap-time of fl...
Development and validation of a multi-residue and multi-class screening method of 44 antibiotics in salmon (Salmo salar) using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry: Application to farmed salmon.
A fast and sensitive multi-residue and multiclass screening method for the simultaneous determination of 44 antimicrobials in salmon muscle, using ultra- high-performance liquid chromatography/time-of...
The findings of previous experiments suggested that polyunsaturated fatty acids(PUFAs) has been linked to anti-hyperlipidemia, and reducing the risk of cardiovascular disease.This is a ran...
Polycystic ovary syndrome (PCOS) is a complex, heterogeneous disorder, which produces in 5-20% reproductive age women. In this study, a nontargeted metabolomics approach based on ultra hig...
RATIONALE: Studying samples of tumor tissue from patients with cancer in the laboratory may help doctors learn more about changes that occur in DNA and identify biomarkers related to cance...
The investigators propose to study the molecular etiology of autism spectrum disorder(ASD) from a genomic, metabolomics and network biology perspective by combining data of gene expression...
RATIONALE: Erlotinib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving erlotinib before surgery may make the tumor smaller and reduce the am...
A method of separation of two or more substances by repeated distribution between two immiscible liquid phases that move past each other in opposite directions. It is a form of liquid-liquid chromatography. (Stedman, 25th ed)
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.
Multiple Sclerosis MS
Multiple sclerosis (MS) is the most common disabling neurological condition affecting 100,000 young adults in the UK. The condition results from autoimmune damage to myelin, causing interference in nerve signaling. Symptoms experienced depend on the pa...