Characterization of the changes in polarity of natural organic matter using solid-phase extraction: introducing the NOM polarity rapid assessment method (NOM-PRAM) (original) (raw)
Journal of Separation Science, 2011
A solid-phase extraction element based on epoxy polymer monolith was fabricated for sorptive enrichment of polar compounds from liquid and gaseous samples. After ultrasonication of the element in an aqueous solution for a given period of time, the thermal desorption (TD) using a pyrolyzer with gas chromatography/mass spectrometry (GC/MS), in which TD temperature was programmed from 50 to 2501C for the analytes absorbed in the element, was used to evaluate the element for basic extraction performance using the aqueous standard mixtures consisting of compounds having varied polarities such as hexanol, isoamyl acetate, linalool, furfural and decanoic acid, in concentrations ranging from 10 mg/L to 1 mg/L. Excellent linear relationships were observed for all compounds in the standard mixture, except decanoic acid. In the extraction of beverages such as red wine, the extraction element showed stronger adsorption characteristics for polar compounds such as alcohols and acids than a non-polar polydimethylsiloxane-based element. This feature is derived from the main polymer structure along with hydroxyl and amino groups present in the epoxy-based monolith polymer matrix.
The Benefits and Limitations of Methods Development in Solid Phase Extraction: Mini Review
Jurnal Teknologi, 2014
Over recent years, there has been an explosive growth of sample preparation techniques. Sample preparation is in most cases meant to be the isolation online or offline concentration of some components of interest or target analytes. Solid phase extraction (SPE) is a very popular technique nowadays in sample preparation. The principal is quite similar with liquid- liquid extraction (LLE) which involves partition of solutes between two phases. But, there are some differences between them and some benefits and limitations of difference types of SPE technique like presented in this paper.
Chromatographia, 2019
This paper presents an overview of the more recent applications of solid-phase extraction (SPE, from January 2015 to September 2018, which have been recorded in Web of Science) in preparation of food and environmental samples. First, the history, milestones, principles, and features of different formats of SPE are discussed. In addition, miniaturization of SPE techniques and comparison of classical SPE and miniaturized SPE-called dispersive micro solid-phase extraction (D-μ-SPE)-are covered. Next, the published applications in extraction and separation of diverse organic and inorganic analytes from a variety of food and environmental samples are classified on the basis of their sorbents including layered double hydroxide, metal organic frameworks, carbon nanotube-based sorbents, graphene-based sorbents, β-cyclodextrinbased sorbents, dendrimer-based sorbents, molecular or ion recognition sorbents, and restricted access materials. Finally, the future trends in this area are discussed. Keywords Solid-phase extraction • Miniaturization • Advanced sorbents • Food samples • Environmental samples Abbreviations 17β-E2 17β-Estradiol 2-PTSC 2-Pyridinecarboxaldehyde thiosemicarbazone AAS Atomic absorption spectrometry ACN Acetonitrile BET Brunauer-Emmette-Teller BP Buckypaper BPA Bisphenol A BSA Bovine serum albumin BTEXs Benzene, toluene, ethylbenzene, and xylenes CD Cyclodextrin CNT Carbon nanotube D-µ-SPE Dispersive micro solid-phase extraction DLR Dynamic linear range DSPE Dispersive solid-phase extraction FAAS Flame atomic absorption spectrometry FTIR Fourier-transform infrared spectroscopy G Graphene GAC Green analytical chemistry GC/NCI-MS Gas chromatography negative chemical ionization mass spectrometry GC Gas chromatography GCB Graphitized carbon black GC-ECD Gas chromatography-electron capture detection GC-FID Gas chromatography flame-ionization detection GC-FPD Gas chromatography-flame photometric detection G-CL Graphene on the zeolite clinoptilolite GC-MS Gas chromatography mass spectrometry
Retention Mechanisms Applied in Solid Phase Extraction for Some Polar Compounds
Two basic mechanisms were applied for studying some polar compounds of pharmaceutical interest (captopril, atenolol, and metformin) by solid phase extraction, using an octadecilsilica based adsorbent. The retention of these compounds was achieved under reversed-phase or ion-pair mechanisms using cartridges containing two different sorbent loadings. The breakthrough parameters (hold-up, breakthrough, and retention volumes) were measured for chosen model solutes from the experimental data obtained by percolating the C18 cartridges with stock solutions for each compound. The experimental curves were fitted by means of Boltzmann’s function, and the regression parameters were used in calculating the breakthrough parameters.
Different methods to select the best extraction system for solid-phase extraction
Journal of Separation Science, 2015
The optimization methods for planning a solid-phase extraction experiment are presented. These methods are based on a study of interactions between different parts of an extraction system. Determination of the type and strength of interaction depends on the physicochemical properties of the individual components of the system. The main parameters that determine the extraction properties are described in this work: The influence of sorbents' and solvents' polarity on extraction efficiency, Hansen solubility parameters and breakthrough volume determination on sorption and desorption extraction step.
Methods and materials for solid-phase extraction
Journal of Chromatography A, 1995
Solid-phase extraction (SPE) with porous solid particles goes back to the early 1970s. However, SPE has become more popular recently due to the availability of more efficient particles and the need to replace liquid extraction procedures that require the use of large quantities of organic solvents. Chemical introduction of acetyl or hydroxymethyl groups into polymeric resins improves the efficiency of SPE by providing better surface contact with aqueous samples. Lightly sulfonated resins display excellent hydrophilicity and improved extraction efficiencies of polar organic compounds over underivatized resins. It is shown that the degree of sulfonation has a major effect on retention of such compounds. Sulfonated resins can also be used for group separation of neutral and basic organic compounds. The advantages of performing SPE with resin-loaded membranes is discussed.
New materials in sorptive extraction techniques for polar compounds
Journal of Chromatography A, 2007
This paper provides an overview of the new developments in material and format technology that improve the extraction of polar compounds in several extraction techniques. They mainly include solid-phase extraction, but there are also other sorptive extraction techniques, such as stir bar sorptive extraction and solid-phase microextraction that use either fibers or in-tube devices. We focus on new synthesised materials that are both commercially available and "in-house". Most novel materials that enhance the extraction of polar compounds are hydrophilic and have large specific surface area; however, we also cover other leading technologies, such as sol-gel or monolith. We describe the morphological and chemical properties of these new sorbents so that we can better understand them and relate them to their capability of retaining polar compounds. We discuss the extraction efficiency for polar compounds when these polymers are used as sorptive material and compare them to other materials. We also mention some representative examples of applications.
Journal of Separation Science, 2003
Silica gel (320 m2g–1, 10 nm) was chemically modified with 3-chloropropyltrimethoxysilane or 3-aminopropyltrimethoxysilane, followed by reaction with aniline, 3-phenylchloropropylamine, or benzylamine. The resulting silicas were characterized by elemental analysis and spectroscopic techniques, namely diffuse reflectance spectroscopy (DRS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and 29Si variable amplitude cross-polarization magic-angle spin nuclear magnetic resonance (VACP-MAS-NMR). The resulting solids were shown to be stable in aqueous and non-aqueous media and were tested as sorbents for pre-concentration of derivatized phenolic compounds (acetyl derivatives of: phenol, o-cresol, m-cresol, p-cresol, 2-ethylphenol, 3-ethylphenol, and 4-ethylphenol) and some organochloride pesticides (endrin, pentachlorobenzene, heptachloro epoxide, hexachlorobenzene, and lindane) in aqueous media. Extractionexperiments were undertaken using a precleaned cartridge (10 cm×10 mm ID) packed with modified silica gel and with commercial C-18 in order to evaluate the influence of the nature of the functional group onretention of the compounds under study. Results showed that silica modified with aniline gave the highest retention for the studied acetylated phenolic compounds. Silica modified with 3-phenylchloropropyl groups exhibited the highest retention for hexachlorobenzene and aldrin, while that modified with benzylamine showed the highest retentionfor eldrin, pentachlorobenzene, and heptachloro epoxide. Lindane was not retained by any of the tested materials.
Technical note Solid phase extraction applied to natural waters: eÅciency and selectivity
2000
Organic matter strongly influences the behaviour of dissolved metals in natural waters. A complete understanding on the nature of these compounds, requires their isolation. The most recently used extraction procedure is reverse-phase liquid chromatography, or solid phase extraction (SPE), by which resins are supposed to retain hydrophobic dissolved material. However, no studies have been done coupling this method with sequential