Degradation of a pharmaceutical in HPLC grade methanol containing trace level formaldehyde.

An anomalous peak was observed in the HPLC/UV analysis of a developmental drug product. High resolution LC/MS revealed that the mass of this degradant was 12 Da greater than the drug substance, corresponding to a net gain of a single carbon atom. The degradant was reproduced by incubating the drug substance with formaldehyde, followed by isolation using normal phase chromatography and structure elucidation by NMR.

Strategies for the analysis of highly reactive pinacolboronate esters.

Pinacolboronate esters (or boronic acid, pinacol esters) are widely used in the Suzuki coupling reaction to connect organic building blocks for the total synthesis of complex molecules. The 2-aminopyrimidine-5-pinacolboronate ester was used as a starting material in the synthesis of a development compound, necessitating a chromatographic purity method to assess its quality. This aryl pinacolboronate ester posed unique analytical challenges due to its facile hydrolysis to the corresponding boronic acid, which is nonvolatile and poorly soluble in organic solvents.

Characterization and resolution of reversed phase HPLC chromatography failure attributed to sulfobutylether-beta-cyclodextrin in a pharmaceutical sample preparation.

A reversed phase HPLC method developed for a drug product formulation using hydroxypropyl-beta-cyclodextrin (HPCD) was rendered ineffective for analyzing a similar formulation containing sulfobutylether-beta-cyclodextrin (SBECD). The active pharmaceutical ingredient (API) and the majority of its impurities became more strongly retained, eluting as an incoherent conglomerate of peaks. Furthermore, this phenomenon was reproduced in subsequent injections of the API reference standard.

Analysis of monoethanolamine by derivatization with Marfey's reagent and HPLC.

A sensitive and selective method for determining the residual monoethanolamine in a developmental drug substance is developed and validated. Marfey's reagent, which is commonly used for the chiral analysis of amino acids, is reacted with the primary amine group of monoethanolamine and then analyzed by high-performance liquid chromatography-UV at 340 nm. Quantitation is performed by a standard addition method by preparing drug substance samples with added monoethanolamine ranging from 0.

Multiresidue determination of pesticides in malt beverages by capillary gas chromatography with mass spectrometry and selected ion monitoring.

A method was developed to determine pesticides in malt beverages using solid phase extraction on a polymeric cartridge and sample cleanup with a MgSO4-topped aminopropyl cartridge, followed by capillary gas chromatography with electron impact mass spectrometry in the selected ion monitoring mode [GC-MS(SIM)]. Three GC injections were required to analyze and identify organophosphate, organohalogen, and organonitrogen pesticides. The pesticides were identified by the retention times of peaks of the target ion and qualifier-to-target ion ratios.

The extraction and infrared identification of gamma-hydroxybutyric acid (GHB) from aqueous solutions.

The chemical analysis of gamma-hydroxybutyric acid (GHB) in most forensic laboratories is complicated by the highly polar nature of the GHB molecule, which makes it unsuitable for direct analysis by gas chromatography (GC). Consequently, a popular analytical approach is to convert GHB into the corresponding lactone or a derivative compound that is then identified by mass spectrometry employed in conjunction with GC (GC/MS). An alternative approach is presented here where GHB may be isolated as a free acid specie from complex aqueous solutions employing a liquid-liquid extraction technique.

Multiresidue pesticide analysis in wines by solid-phase extraction and capillary gas chromatography-mass spectrometric detection with selective ion monitoring.

A method was developed to determine pesticides in wines. The pesticides were extracted from the wine using solid-phase extraction on a polymeric cartridge, and the coextractives were removed with an aminopropyl-MgSO(4) cartridge. Analysis was performed using capillary gas chromatography with electron impact mass spectrometric detection in selective ion monitoring mode (GC-MSD/SIM).

Photoreduction of the chloropropionic acid of carfentrazone-ethyl in sodium sulfide [corrected].

The purpose of this study was to determine whether the conversion of carfentrazone-chloropropionic acid to carfentrazone-propionic acid in sunlit rice paddies is attributed to photoreduction. Model solutions (Na2S with quinoids) irradiated by laboratory ultraviolet light dechlorinated carfentrazone-chloropropionic acid (1.6-28.