Simultaneous determination of neutral sugars, alditols and anhydrosugars using anion-exchange chromatography with pulsed amperometric detection: Application for marine and atmospheric samples

Abstract

An improved high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method is described for the simultaneous determination of neutral sugars (hexoses, pentoses and deoxysugars), alditols and anhydrosugars commonly found in atmospheric and marine samples. The method uses a CarboPac MA1 column, at a flow rate of 0.3 mL min-1 , and a NaOH gradient (250-700 mM). The proposed method applies a temperature gradient (from 25 to 28 °C) to the column for the first 30 min of the analysis, followed by a constant temperature at 28 °C until the end of the analysis. These analytical conditions allowed the separation of 15 out of 17 carbohydrates in 75 min with resolution factors better than 0.5 for the critical pairs levoglucosan/arabitol, galactosan/arabinose, arabinose/mannose and glucose/xylose. The application of this method to field samples revealed that anhydrosugars represented 53% of total neutral carbohydrates (TCHO) in total suspended atmospheric particles (TSP), whereas they were detected for the first time in marine particulate organic matter (POM) and high-molecular-weight dissolved organic matter (HMWDOM) samples accounting 2% and 3% of TCHO, respectively. Levoglucosan and/or galactosan were the major anhydrosugars in all samples however, their concentrations are undoubtedly underestimated because hydrolysis was applied to the marine samples prior to the HPAEC-PAD analysis. Despite this underestimation, their presence in the marine samples clearly indicates possible terrestrial input most likely via atmospheric deposition as these compounds are considered terrestrial burring biomass tracers. Finally, deoxysugars were also detected for the first time in the TSP sample representing 1% of TCHO, while alditols accounted for 0.4% and 0.3% of TCHO in POM and HMWDOM, respectively.

The Biogeochemistry of Marine Polysaccharides: Sources, Inventories, and Bacterial Drivers of the Carbohydrate Cycle

“…Acid hydrolysis can also be followed by high-performance anion exchange chromatography with pulsed amperometric detection to separate and quantify the monosaccharide composition of diverse samples (Borch & Kirchman 1997). Specific sample preparation permits analysis of neutral, amino, and acidic sugars in high-molecular-weight DOM and POM (Engel & Handel 2011); anhydrosugars can also be measured using high-performance anion exchange chromatography with pulsed amperometric detection under specific chromatographic conditions (Nouara et al 2019). For POM analysis, acid hydrolysis of increasing severity (Quijada et al 2015) and/or a variety of different POM extraction techniques (Miyajima et al 2001) can provide an indication of the structure and matrix in which carbohydrates are found (Lin & Guo 2015).…”

A fast, single column high‐performance anion exchange chromatography with pulsed amperometric detection method for the determination of saccharides in atmospheric aerosol samples

“…The method discussed in this work is an improvement over reported methods that are unable to completely resolve the anhydro sugars, which are the main analytes of an atmospheric aerosol sample, from other saccharides present in the sample. For example, with a 95-minute method, which also used a temperature gradient, the resolution between arabinose and galactosan was only 1.3 [18]. In another example, galactosan was poorly resolved from mannose and glucose, both having resolution values of 1.3 [14].…”

“…It also includes the sugar alcohols xylitol, sorbitol, and mannitol. HPAE-PAD is the most widely used method to determine saccharides from atmospheric aerosol samples [13][14][15][16][17][18]. HPAE-PAD separates native carbohydrates (i.e., underivatized) at high pH (>12) and detects them by PAD on a gold working electrode.…”

“…Table 2 lists HPAE-PAD methods for saccharide determination in atmospheric aerosol samples that resolve more than a few saccharides with a single column. These typically use a CarboPac MA1 column for separation of anhydro sugars and sugar alcohols, but these methods are not ideal for a fast analysis using automation, as the run times are typically very long [12,18,20]. A recently reported single column method had a run time of 95 min , with some saccharide pairs being poorly resolved [18].…”

“…These typically use a CarboPac MA1 column for separation of anhydro sugars and sugar alcohols, but these methods are not ideal for a fast analysis using automation, as the run times are typically very long [12,18,20]. A recently reported single column method had a run time of 95 min , with some saccharide pairs being poorly resolved [18]. We recently published a method that resolves some of the difficult-toresolve saccharide pairs using a CarboPac MA1 column.…”