Rapid detection of biologically active natural products plays a strategic role in the phytochemical investigation of crude plant extracts. In order to perform an efficient screening of the extracts, both biological assays and HPLC analysis with various detection methods are used. Combined techniques such as HPLC coupled to UV photodiode array detection (LC/UV) and to mass spectrometry (LC/MS or...

The three major active isoflavonoids (calycosin-7-O-β-glucoside, isomucronulatol 7-O-β-glucoside, formononetin) and two main saponins (astragaloside I, astragaloside IV) in an extract of Radix Astragali were determined using rapid, sensitive, reliable HPLC/UV and LC-ESI-MS/MS methods. The separation conditions employed for HPLC/UV were optimized using a phenyl-hexyl column (4.6 × 150 mm, 5 μm) ...

Ribavirin, a nucleoside analog, is administered in combination with interferon to patients with chronic hepatitis C. To evaluate the feasibility of ribavirin therapeutic drug monitoring, we investigated the influence of blood collection and preanalytical conditions on ribavirin concentrations and compared the results obtained from interlaboratory blind tests by 3 laboratories using different an...

Derivatization of neutral steroids for increasing sensitivity in liquid chromatography/negative atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) has been examined. Under APCI conditions, gas-phase electrons are provided by the corona discharge and captured by electron-affinitive compounds. In negative APCI-MS, therefore, ultrahigh sensitivity can be obtained by tagging neutr...

A rapid and reliable method enabling high-throughput sample analysis for quicker data generation, detection, and monitoring of eight selected steroid hormones in water matrixes was developed and validated. Our approach is based on a novel sample introduction method, the laser diode thermal desorption/atmospheric pressure chemical ionization (LDTD/APCI) coupled to tandem mass spectrometry (MS/MS...

The applicability of Supercritical Fluid Chromatography (SFC) can be substantially enhanced by coupling SFC to Mass Spectrometric detection (MSD). In this Technical Overview, two instrument configurations are described that can be used to connect the Agilent 1260 Infinity Analytical SFC to a mass spectrometer either using an atmospheric pressure chemical ionization (APCI) or an electrospray (ES...

The Commission Decision of EC dated 20 June 2003, on emergency measures concerning hot chilli and hot chilli products coming into any EC member state, required that the consignments of such products should be accompanied by an analytical report showing that they are free of artificial dye Sudan I. The opportunity to set a confirmatory method is evident, and the paper proposes a HPLC/APCI-MS met...

Narcissus is widely used for cut flowers and potted plants, and is one of the most important commercial bulbous flowers in the floricultural industry. In this study, ten carotenoid and eighteen flavonoid compounds from the perianths and coronas of fifteen narcissus cultivars were measured by HPLC-APCI-MS/MS and UPLC-Q-TOF-MS/MS. Among these, six carotenoids, a total of seventeen flavonols and c...

The purpose of the present work was to evaluate the synergistic effect of ionization type, sample preparation technique, and bio-fluid on the presence of matrix effect in quantitative liquid chromatography (LC)-MS/MS analysis of illicit drugs by post-column infusion experiments with morphine (10-microg/mL solution). Three bio-fluids (urine, oral fluid, and plasma) were pretreated with four samp...

Bis(2-hydroxyethylthio)alkanes and bis(2-hydroxyethylthioalkyl)ethers are important biological and environmental degradation products of sulfur mustard analogs known as sesqui- and oxy-mustards. We used atmospheric pressure chemical ionization mass spectrometry (APCI MS) to acquire characteristic spectra of these compounds in positive and negative ionization modes. Positive APCI mass spectra ex...