Liquid chromatography-mass spectrometry has evolved from a topic of mainly research interest into a routinely usable tool in various application fields. With the advent of new ionization approaches, especially atmospheric pressure, the technique has established itself firmly in many areas of research. Although many applications prove that LC-MS is a valuable complementary analytical tool to GC-...

The current study applied gas chromatography-mass spectrometry (GC–MS), liquid (LC-MS), and thermal desorption direct analysis in real-time mass (TD-DART-MS) methods to the of black pepper (Piper nigrum L.) samples from different countries. powder were analyzed directly by TD-DART-MS without any extraction, but for GC–MS LC-MS methods, a methanol extraction procedure was employed before analysi...

The results of meconium specimens and fortified samples screened for drugs of abuse by both enzyme-linked immunosorbent assay (ELISA, Immunalysis) and biochip microarray (Randox) methods were compared. The ELISA method was semi-automated using a TECAN Genesis. The Randox assay used the Randox Evidence Investigator system. Previously validated gas chromatography-mass spectrometry (GC-MS), GC-GC-...

A series of acylated derivatives of 3,4-methylenedioxy-methamphetamine (3,4-MDMA) are prepared and evaluated in gas chromatography-mass spectrometry (GC-MS) studies. The perfluoroalkyl amides of 3,4-MDMA show the lowest GC retention, while the aromatic amides such as the benzamide show the greatest retention on the dimethylpolysiloxane stationary phase (Rtx-1). The mass spectral properties of t...

A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (...

Polybrominated diphenyl ethers (PBDEs), commonly used flame retardants, are under scrutiny as a result of their global presence and rapid bioaccumulation. Legislative and commercial groups have initiated programs to reduce or eliminate specific PBDE congeners as a result of their potential health threat. This application note will demonstrate a gas chromatography/mass spectrometry (GC/MS) analy...

different solvent extracts of a red algae, hypnea flagelliformis,and two brown algae, cystoseira myrica and sargassum boveanum, collected from the persian gulf coast were subjected to different bioassays including: 1,1-diphenyl-2-picrylhydrazyl (dpph) free radical scavenging assay, antibacterial and antifungal activity by thin layer chromatography (tlc)-bioautography, agar disc diffusion (add) ...

Our understanding of formation processes, physical properties, and climate/health effects of organic aerosols is still limited in part due to limited knowledge of organic aerosol composition. We present speciated measurements of organic aerosol composition by two methods: in situ thermaldesorption proton-transfer-reaction mass spectrometry (TDPTR-MS) and offline two-dimensional gas chromatograp...

Human odor detection technologies have drawn attention due to the wide possibility of potential applications they open up in areas such as biometrics, criminal investigation and forensics, search for survivors under rubble, and security checkpoint screening. Gas chromatography/mass spectrometry (GC/MS) has been the most successful and powerful analytical approach developed to date for human odo...

Successful application of the Hadamard transform (HT) technique to gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) is described. Novel sample injection devices were developed to achieve multiple sample injections in both GC and LC instruments. Air pressure was controlled by an electromagnetic valve in GC, while a syringe pump and Tee connector we...