Comparison of Sorbents Using Semipolar to Highly Hydrophilic Compounds for a Sequential Solid-Phase Extraction Procedure of Industrial Wastewaters

Abstract

Untreated and biologically cleaned industrial wastewaters contain huge amounts of both hydrophilic and hydrophobic compounds. Due to breakthrough effects, only a few percent of the dissolved organic carbon is usually extracted by solid-phase extraction methods. Methods for screening analysis have not faced that problem sufficiently yet. To extract more hydrophilic compounds, solid-phase sorbent characteristics had to be evaluated in this study. Recovery studies were carried out with 21 hydrophilic aromatics including carboxy acids, sulfonates, aldehydes, ketones, thiols, and phenols at a level of 1−2 μmol/L. Both silica gel based sorbents and polymeric materials were tested at neutral to acidic pH values and extraction volumes up to 200 mL. It was found that poly(styrene−divinylbenzene) sorbents are a powerful tool for the enrichment of hydrophilic aromatic substances. Most of the tested compounds could be extracted at recovery rates of >80%. The quantitative extraction of thiols as well as (aminohydroxy)disulfonic acids remains an unsolved problem. Finally, combination of different solid sorbents and pH changes is suggested for sequential extraction of heavily loaded industrial wastewaters. Advantages and limitations are discussed and an example of its usefulness is given.

Determination of the pesticides considered as endocrine‐disrupting compounds (EDCs) by solid‐phase extraction followed by gas chromatography with electron capture and mass spectrometric detection

“…Much improved recoveries, higher than 75%, were obtained on the SDB-type disk. These results support other findings reporting that recoveries of virtually all of the routinely determined nitrogen and phosphorus containing herbicides are considerably higher when using SDB as the adsorbent material, than octadecyl silica (C18) [39,40]. The higher retention of SDB sorbents over C18 silicas is due to strong p -p interaction types between analytes and the SDB matrix in addition to common hydrophobic interactions [41].…”

GC-MS and LC-MS evaluation of pesticide degradation products generated through advanced oxidation processes: An overview

“…Additional and very useful structural information on DPs can be obtained using the chemical ionization mode (CI), especially for determining the DPs' molecular weights (Mw). Few studies re ly on GC-MS with chemical ionization (CI) mode for DP identification, mainly because in quadrupole technology additional instrumentation is required for positive and negative CI analysis [10,20]. In ion trap (IT) technology, switching from EI to CI can be achieved very easily providing rapid information on the molecular weight of the DPs.…”

“…During a third and fourth step, samples can be acidified to pH 4.5 and pH 2 . 5 , re s p e c t ive ly, for ex t raction of the majority of acidic compounds with a polymeric or carbon type sorbent [20]. The advantages of Lichrolut EN and Isolute ENV+ polymeric sorbent materials over C 18 materials are that polymeric sorbents can be used at pH 2 − 13 without decomposition and can therefore extract a large ar ray of DPs with different polarities.…”

Influence of different flow conditions on the occurrence and behavior of potentially hazardous organic xenobiotics in the influent and effluent of a municipal sewage treatment plant in Germany: an effect-directed approach

“…As a consequence, recoveries for individual substances are often markedly reduced [17]. Some SPE methods, especially for the EDA of organic xenobiotics in wastewater, are described in earlier literature [11,12,18], but there are continuous advancement and simplification of wide-spectrum SPE procedures due to the development of new polymeric sorbents. In the multicomponent methods of recent work, Oasis HLB from Waters (Milford, MA, USA) is commonly applied as it is able to extract many different organic environmental chemicals at neutral pH to equally high efficiencies [16,[19][20][21].…”