Determination of Sulfate in Coastal Salt Marsh Sediments With High-Chloride Concentration by Ion Chromatography: A Revised Method

Abstract

In order to elucidate the relationship between sulfate reduction and mineralization of organic matter in coastal sediments, the content of sulfate in sediment samples should be measured. Chloride, sulfate, bromide, nitrate, and phosphate are the standard anions in coastal sediment samples. Ion chromatography (IC) is one of the popularly used techniques for determinations of these anions. However, the peaks of the fi ve anions in the IC system coincide with each other under high chloride conditions when using the normal method. In this article, an improved, highly sensitive method for simultaneous separation and determination of sulfate, bromide, nitrate, and phosphate in the samples with high chloride concentration is established and evaluated by IC. In high concentrations of chloride samples, the effects of eluent concentration on the retention time and separation of other anions are studied. The peaks of these anions can be well separated on an AS11 ion-exchange column by a low concentration of NaOH eluent (10 mM). in one injection. Gradient elution is helpful to shorten retention time, especially for phosphate. The method detection limit of sulfate is 0.091 mg·L -1 . The recovery of sulfate ranged from 100.5% to 106.8%, when the concentrations of standard solution are close to those of the samples. This technique was validated by determining the content of sulfate and chloride in coastal salt marsh sediment samples.

Impacts ofDesulfobacteralesandChromatialeson sulfate reduction in the subtropical mangrove ecosystem as revealed by SMDB analysis

“…Total nitrogen (TN) was determined by acid fumigation method and followed the method described by Harris et al (2001). TP was determined by alkali digestion method and followed the method described by Yang et al (2013). Fe concentration was determined by Atomic Absorption Spectrophotometer (GBC932, Australia) according to the instruction.…”

Coupling mechanisms of S–Fe–P in surface sediments under the stresses of high salinity and heavy metals in coastal rivers

“…Sulfate in sediments was extracted according to extraction method (Yang et al 2013) and was determined by barium chromate spectrophotometry (HJ/T 342-2007, Chinese standard). In brief, the vacuum freeze-dried sample was mixed with Milli-Q water (mass ratio 5: 1) and then was stirred for 24 h. After centrifugation (3000g, 15 min), the supernatant was added with zinc acetate and sodium hydroxide solutions to precipitate sulfide before filtered through 0.45-um membrane in an anaerobic incubator.…”

L-Cysteine Synthase Enhanced Sulfide Biotransformation in Subtropical Marine Mangrove Sediments as Revealed by Metagenomics Analysis

“…The AS was determined using the barium sulfate turbidimetry method [20]. The total phosphorus (TP) content was determined using the alkali digestion method through the Dionex ICS-2500 Reagent-Free Ion Chromatograph (Dionex Corp., Sunnyvale, CA, USA) [21]. The iron concentration was determined using atomic absorption spectrophotometry (GBC932, Varian, Australia).…”