Determination of picomolar levels of flavins in natural waters by solid-phase ion-pair extraction and liquid chromatography

Distribution of Extracellular Flavins in a Coastal Marine Basin and Their Relationship to Redox Gradients and Microbial Community Members

“…Although known to rapidly photodegrade and exhibit strong surface water diurnal variations, concentrations were still detectable in the photic zone, likely indicating recent cellular production. RF concentrations fell within the range of the only two previously reported LC/MS measurements ranging from <0.7 to 4.4 pM in the Baja California Coast, Mexico and 45 to 128 pM in the Hood Canal, WA. , The RF concentrations also fall within the range reported from a number of studies from the 1980s–1990s which recorded marine measurements based on fluorescence and found concentrations ranging from 0 to 100 pM. ,− Another study investigated vertical distributions of total flavins (reported only as relative fluorescence) in the Caribbean and Black Sea and observed an increase in flavin fluorescence with depth. The elevated fluorescence with depth was attributed to diffusion from sediments and/or elevated production in sulfidic bottom waters similar to the increase in concentration observed below the sill depth at SPOT.…”

“…27,47 The RF concentrations also fall within the range reported from a number of studies from the 1980s-1990s which recorded marine measurements based on fluorescence and found concentrations ranging from 0-100 pM. 23,[48][49][50] Another study 51 occurring in the photic zone. [51][52] Despite being degradation products of RF and FMN, select studies have found that LC and LF may serve important roles in the microbial community as quorum sensing molecules.…”

“…Flavins are known to rapidly photodegrade, forming the degradation products lumichrome (LC) and lumiflavin (LF) . Furthermore, the few studies that have attempted to investigate environmental flavin concentrations via fluorometric techniques have found them to be in trace concentrations (pM range), and therefore a preconcentration step is required prior to quantification . Here we present environmental concentrations of the flavins (FMN and RF) and their degradation products LC and LF measured in the water column and pore waters of a coastal marine environment in San Pedro Basin (Supporting Information (SI) Figure S2) using a newly adapted, compound-specific, high performance liquid chromatography mass spectrometry (LC/MS) method.…”

Capillary liquid chromatographic determination of cellular flavins

“…Since RF participates in biochemical redox reactions in the form of two coenzymes, FMN and FAD, development of analytical techniques for the determination of the concentration of each flavin is helpful for the studies of the roles of these compounds in biological systems. A number of conventional high performance liquid chromatography (HPLC) methods [6][7][8][9][10][11][12] have been reported for the simultaneous analysis of the three flavins. More recently, capillary electrophoresis (CE) [13][14][15][16] has also been applied to separate and determine RF, FMN and FAD in different matrices because of its high resolution, rapid analysis time, and small sample requirement.…”

“…As flavins are naturally occurring fluorescent compounds [17], most of HPLC [6][7][8][9][10][11] and CE [13][14][15][16] methods for analysis of flavins use fluorescence for detection, which allows their selective detection from other compounds present in the sample matrix, especially a complicated biological sample. Compared with fluorescence detection, UV detection is more popular in LC although its sensitivity is lower.…”