Styrene-divinylbenzene Copolymer Sorbent Research Articles

#2799 Myoglobin removal by hemadsorption: ex-vivo adsorption kinetics

Abstract Background and Aims Myoglobin, due to its molecular weight of 17 kDa and a Einstein-Stoke radius greater than expected, is classed as a middle molecular weight uremic toxin and presents a two-compartment model of distribution in the body. Rhabdomyolysis is a condition in which muscle cell content including myoglobin, are released into blood circulation due to severe injury to the muscle. Circulating myoglobin induces renal injury with several mechanisms: reduced concentration of nitric oxide in medullary renal arterioles, production of free radicals with oxidative stress, tubular necrosis as a consequence of tubular obstruction by myoglobin and cellular debris. A possible therapeutic option is the use of High Cut-off membranes but with the risk of significant loss of albumin and other proteins. The use of adsorption can overcome these limitations. The aim of our study is to assess the adsorption of myoglobin with neutral microporous styrene-divinylbenzene copolymer sorbent (e.g., HA330/380, Jafron Biomedical CO, Lts, Zhuhai City, China). Method Using a downscaled module of HA380 Cartridge, we set up an ex-vivo circulation experiment in which 1 liter of plasma containing 0.1 mg of myoglobin was pumped through the cartridge. We collected samples (3 mL) at different timepoints to measure Myoglobin concentration. We calculated the removal ratio (RR) and mass adsorbed at a given timepoints. Results Initial myoglobin concentration was 99.3 ng/ml. Final myoglobin concentration after 4 hours of experiment was 30.6 ng/ml. Removal Ratio at 4 hour was 69 % and mass adsorption of 0.068 mg of myoglobin. Conclusion To our knowledge, this is the first experiment that assessed the adsorption capacity of polystyrene-divinylbenzene sorbent. Our study, demonstrated high adsorption capacity in the first 4 hours of treatment therefore, confirming the possibility to use adsorption as an effective treatment option in rhabdomyolysis and avoiding complications associated to current dialytic treatment.

Groundwater dating with dissolved organic radiocarbon: A promising approach in carbonate aquifers

A complete hydrogeological understanding of the deep Upper Jurassic carbonate aquifer in the South German Molasse Basin is essential for the future development of this important drinking water resource and geothermally used system.Water chemistry data, δ13CDIC, 14C of the dissolved inorganic carbon (14CDIC) and stable water isotope (δ18O and δD) measurements have been used to evaluate a promising groundwater dating approach with 14C of dissolved organic carbon (14CDOC). The pre-concentration of dissolved organic matter (DOM) was performed by the easy applicable solid phase extraction (SPE) with a styrene-divinylbenzene copolymer sorbent (PPL).Based on the sampling campaign of seven groundwater wells conducted between 2017 and 2019, it was shown that the groundwater is mainly of Ca–HCO3 type with some evidence of ion exchange between Ca2+ and Na+ at two of the investigated wells. The δD values ranged from −89.4‰ to −70.9‰ while δ18O values varied between −12.5‰ and −9.8‰. The obtained stable water isotope signatures indicated that the groundwater is of meteoric origin and was recharged during warm climate (Holocene), intermediate climate and cold climate (Pleistocene) infiltration conditions.The measured 14CDOC activities varied from 5.7 pmC to 51.1 pmC and the calculated piston-flow water ages (ORAs) ranged from 4200 years to 25,248 years using an initial 14C0DOC of 85 pmC. The calculated ORAs showed a very good correlation to the infiltration temperature-sensitive δ18O values which were affirmed with noble gas infiltration temperatures for two wells after Weise et al. (1991) and were also in good accordance with the atmospheric temperature record of the northern hemisphere from Dokken et al. (2015).The results reflect a consistent hydrogeological picture of the carbonate aquifer, which also supports the applicability of the SPE-PPL method for 14CDOC dating in groundwater with a low DOC content (<1 mg/l). In contrast, 14CDIC activities of 1.4 pmC to 21.3 pmC led to geochemically corrected piston-flow ages between 8057 years and >30,000 years and generally to an overestimation of the apparent water ages.This study gives insights into the promising approach of 14CDOC groundwater dating in carbonate aquifers with low DOC contents and allows future sustainable groundwater resource management of the investigated aquifer system.

Control of Adsorption/Desorption of Anions Based on Redox of Solid Phase Coated with Cobalt Complexes

The adsorption-desorption behaviors of hydrophobic anion on the solid phase coated with redox-active metal complexes (ML2+/0 ; M, CoIII/II ; L−, pyridylazo compounds) were investigated. The combination of a cobalt complex of poly vinyl phenol introduced with a 2-pyridylazo group and a solid-phase extraction cartridge packed with styrene-divinyl benzene copolymer sorbent showed the highest adsorption capacity for methyl orange as a hydrophobic anion. The percentage adsorption of methyl orange (1.0 μmol) on this solid phase was more than 99%, even in the presence of a 100-fold stoichiometric excess of coexisting anions (ClO4−, Cl−). Methyl orange molecules were desorbed by reducing the cobalt complexes in the solid phase with a 1.0 × 10−2 M ascorbic acid solution.

Determination of Tricyclazole in Water Using Solid Phase Extraction and Liquid Chromatography

A method for determination of tricyclazole in water using solid phase extraction and high performance liquid chromatography (HPLC) with UV detection at 230 nm and a mobile phase of acetonitrile:water (20:80, v/v) was developed. A performance comparison between two types of solid phase sorbents, the C18 sorbent of Supelclean ENVI-18 cartridge and the styrene-divinyl benzene copolymer sorbent of Sep-Pak PS2-Plus cartridge was conducted. The Sep-Pak PS2-Plus cartridges were found more suitable for extracting tricyclazole from water samples than the Supelclean ENVI-18 cartridges. For this cartridge, both methanol and ethyl acetate produced good results. The method was validated with good linearity and with a limit of detection of 0.008 µg L−1 for a 500-fold concentration through the SPE procedure. The recoveries of the method were stable at ∼80% and the precision was from 1.1 − 6.0% within the range of fortified concentrations. The validated method was also applied to measure the concentrations of tricyclazole in real paddy water.

Calibration of a passive sampling device for time‐integrated sampling of hydrophilic herbicides in aquatic environments

Two types of solid-phase materials, a styrenedivinylbenzene copolymer sorbent (embedded in a SDB-XC Empore disk) and a styrenedivinylbenzene copolymer sorbent modified with sulfonic acid functional groups (embedded in a SDB-RPS Empore disk), were compared as a receiving phase in a passive sampling device for monitoring polar pesticides. The SDB-XC Empore disk was selected for further evaluation, overlayed with either a polysulfone or a polyethersulfone diffusion membrane. The target herbicides included five nonionized herbicides (simazine, atrazine, diuron, clomazone, and metolachlor) and four phenoxy acid herbicides (dicamba, (2,4-dichlorophenoxy)acetic acid [2,4-D], (4-chloro-2-methylphenoxy)acetic acid [MCPA], and triclopyr) with log octanol/water partition coefficient (log K(OW)) values of less than three in water. Uptake of these herbicides generally was higher into a device constructed of a SDB-XC Empore disk as a receiving phase covered with a polyethersulfone membrane compared to a similar device covered with a polysulfone membrane. Using the device with a SDB-XC Empore disk covered with a polyethersulfone membrane, linear uptake of simazine, atrazine, diuron, clomazone, and metolachlor was observed for up to 21 d, and daily sampling rates of the herbicides from water in a laboratory flow-through system were determined. The uptake rate of each nonionized herbicide by the Empore disk-based passive sampler was linearly proportional to its concentration in the water, and the sampling rate was independent of the water concentrations over the 21-d period. Uptake of the phenoxy acid herbicides (2,4-D, MCPA, and triclopyr) obeyed first-order kinetics and rapidly reached equilibrium in the passive sampler after approximately 12 d of exposure. The Empore disk-based passive sampler displayed isotropic kinetics, with a release half-life for triclopyr of approximately 6 d.

Determination of aromatic primary amines at μg l −1 level in environmental waters by gas chromatography–mass spectrometry involving N-allyl- N′-arylthiourea formation and their on-line pyrolysis to aryl isothiocyanates

Derivatization of aromatic primary amines to N-allyl- N′-arylthioureas by reaction with allyl isothiocyanate and GC–MS of the derivatives, when pyrolysis to aryl isothiocyanates occurs in the heated injector, has been used to determine aromatic amines in the range 0.5–50 μg l −1 with a correlation coefficient, r, in the range 0.9902–0.9992. The limit of detection ranged 8 to 30 ng l −1 when 60 ml of sample were preconcentrated, after derivatization, on a styrene–divinylbenzene copolymer sorbent. The pyrolytic cleavage of sym- and unsym-diaryl or alkyl-/arylthioureas has been rationalized. The chromatography of isothiocyanates is much superior to that of aryl amines and the specific mass fragmentation permits positive identification of amines. The method has been applied to spiked drinking water, groundwater and river water samples, when the recovery ranged from 84 to 109% with RSD of 5–9%, and to detect aromatic amines formed by reductive cleavage of azo dyes in effluents when the recovery of amine was in the range 81–95% with RSD 8–15%. The method is not applicable to nitroanilines.

Simultaneous determination of ammonia, aliphatic amines, aromatic amines and phenols at µg l–1 levels in environmental waters by solid-phase extraction of their benzoyl derivatives and gas chromatography-mass spectrometry

Low concentrations of phenols and amines in environmental waters and their low breakthrough volume during solid-phase extraction (SPE) hinder the detection of phenols and aromatic amines, whereas ammonia and aliphatic amines are not suitable for SPE. Pre-column derivatization to arylbenzoates and N-alkyl- or N-arylbenzamides and their GC-MS is proposed to separate and determine phenols and amines in aqueous samples in the range 0.1–100 μg l−1 with correlation coefficients in the range 0.9910–0.9992. The limit of detection ranged from 7 to 39 ng l−1 for most analytes (90 ng l−1 for 2,3,6-trichlorophenol and 20 μg l−1 for ammonia) when 80 ml of sample were preconcentrated, after derivatization, on a styrene–divinylbenzene copolymer sorbent. The developed method was applied to spiked drinking water, groundwater and river water samples, and was used to detect halo-phenols in paper mill effluents. The average recovery ranged from 96 to 110% with RSD of 4–12%. The described method is rapid and can be applied to control the water quality of environmental waters with respect to three important classes of organic pollutants and ammonia.

Comparative study of the use of high-performance liquid chromatography and capillary electrophoresis for determination of phenolic compounds in water samples

A comparative study of high-performance liquid chromatography (HPLC) and capillary zone electrophoresis (CZE) for determination of eleven EPA priority phenols in water samples is discussed. The repeatability, linearity and detection limits of both methods are compared. A solid-phase extraction method using a highly cross-linked styrene-divinylbenzene copolymer sorbent is used for the off-line preconcentration process in order to determine these compounds in water at low levels. Both methods are used to determine phenolic compounds in Ebro river and industrial waste water. Identification was achieved by comparison of the UV spectra corresponding to the different peaks, acquired with a diode-array detector, with those in a spectral library.