Search results for "solid phase"
showing 10 items of 360 documents
Cloud point–dispersive μ-solid phase extraction of hydrophobic organic compounds onto highly hydrophobic core–shell Fe 2 O 3 @C magnetic nanoparticles
2012
Abstract A novel two-step extraction technique combining cloud point extraction (CPE) with dispersive micro-solid phase extraction (D-μ-SPE) is presented in this work for the first time. The method involves initial extraction of the target analytes by CPE in the micelles of a non-ionic surfactant medium; then highly hydrophobic polysiloxane-coated core–shell Fe 2 O 3 @C magnetic nanoparticles (MNPs) are used to retrieve the micellar phase. In that manner, the micellar phase containing the analytes is the target of the D-μ-SPE step rather than the analytes directly. MNPs are then collected by the application of an adscititious magnetic field overcoming the need for specific steps associated …
Miniaturized solid-phase extraction techniques
2015
More than 80% of analysis time is spent on sample collection and sample preparation, so sample preparation is a critical part of the analytical process. Traditionally, liquid-liquid extraction was developed and employed to screen for general unknowns. However, solid-phase extraction (SPE) is becoming highly popular as an alternative, due to its simplicity and economy in terms of time and solvent. This review summarizes the current state of the art and the future prospects for green analytical chemistry with special emphasis on environment-friendly sample-preparation techniques based on the solid phase. We discuss in detail miniaturized SPE techniques, based on the most relevant, most repres…
Sample Preparation to Determine Pharmaceutical and Personal Care Products in an All-Water Matrix: Solid Phase Extraction
2020
© 2020 by the authors.
Polish Yellow Sweet Clover (Melilotus officinalis L.) Honey, Chromatographic Fingerprints, and Chemical Markers
2017
A case study of Polish Melilotus officinalis honey was presented for the first time. Gas chromatography–mass spectrometry (GC-MS) (after steam distillation, Soxhlet extraction, ultrasonic solvent extraction, and solid phase extraction (SPE)) and targeted high performance liquid chromatography with a photodiode array detector (HPLC-PAD) were applied to determine the characteristic components of honey. While ubiquitous in most honeys, carbohydrates, terpene derivatives, and phenylacetic acid dominated in the Soxhlet extracts (25.54%) and in the application of SPE (13.04%). In addition, lumichrome (1.85%) was found, and may be considered as a marker of this honey. Due to the presence of these …
On-line analysis of carbonyl compounds with derivatization in aqueous extracts of atmospheric particulate PM10 by in-tube solid-phase microextraction…
2011
Abstract A new device for carbonyl compounds based on coupling on-line and miniaturizing both, sample pretreatment and chromatographic separation, is reported. Two capillary columns, a GC capillary column (95% methyl–5% phenyl substituted backbone, 70 cm × 0.32 mm i.d., 3 μm film thickness) in the injection valve for in-tube solid-phase microextraction (IT-SPME) and a Zorbax SB C18 (150 mm × 0.5 mm i.d., 5 μm particle diameter) LC capillary column were employed. Different combinations of IT-SPME and derivatization using 2,4-dinitrophenylhydrazine (DNPH) were examined for mixtures containing 15 carbonyl compounds (aliphatic, aromatic and unsaturated aldehydes and ketones). A screening analys…
Liquid Chromatographic Analysis of Amphetamine and Related Compounds in Urine Using Solid-Phase Extraction and 3,5-Dinitrobenzoyl Chloride for Deriva…
1997
A chromatographic method for the analysis of amphetamine and related compounds in urine using 3,5-dinitrobenzoyl chloride (3,5-DNB) as a labeling reagent is presented. This assay is based on the employment of solid-phase extraction (SPE) cartridges for sample cleanup and derivatization. Experimental conditions are optimized for the simultaneous derivatization of ephedrine, norephedrine, pseudoephedrine, beta-phenylethylamine, amphetamine, methamphetamine, and 3-phenylpropylamine. The derivatives formed are separated in a LiChrospher 1000 RP18 (125 x 4-mm i.d., 5-microns film thickness) analytical column using a water-acetonitrile gradient elution and detected at 254 nm. Derivatization in C1…
Sequential-injection determination of traces of disodium phenyl dibenzimidazole tetrasulphonate in urine from users of sunscreens by on-line solid-ph…
2005
Abstract A sensitive and selective method to determine disodium phenyl dibenzimidazole tetrasulphonate (PDT) in the urine of sunscreen users, which is suitable for studies on body accumulation/excretion is proposed. On-line solid-phase extraction allows the analyte to be retained and subsequentely eluted, using a strong anion exchange (SAX) microcolumn. Standard addition calibration was carried out with only one standard. The wavelengths of excitation and emission were 330 and 454 nm, respectively. The method allows PDT to be determined in both, spiked and unspiked human urine samples, without any pre-treatment. Results obtained for spiked urine samples (40–200 ng ml −1 ) showed the accurac…
Determination of 3-(4′-methylbenzylidene)camphor and its metabolite 3-(4′-carboxybenzylidene)camphor in human semen by solid-phase extraction and liq…
2015
An analytical method for the determination of the controversial UV filter 3-(4′-methylbenzylidene)camphor (MBC) and its metabolite 3-(4′-carboxybenzylidene)camphor (CBC) in human semen is presented. The method is based on the simultaneous hydrolysis of phase II conjugates and protein precipitation, followed by solid-phase extraction (SPE) and liquid chromatography tandem mass spectrometry (LC-MS/MS) detection. The proposed method was validated by analyzing spiked analyte-free human semen samples. Matrix-matched calibration using an analyte-free semen pool was employed. Satisfactory recoveries (92–114%) were obtained using this calibration methodology, thus showing the accuracy of the propos…
Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry.
2013
Solid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about novel methodological and instrumental solutions in relation to different variants of solid phase extraction techniques, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE) and magnetic solid phase extraction (MSPE) is presented, including prac…
New micromethod combining miniaturized matrix solid-phase dispersion and in-tube in-valve solid-phase microextraction for estimating polycyclic aroma…
2008
Abstract Miniaturized matrix solid-phase dispersion (MSPD) was developed for the extraction of common polycyclic aromatic hydrocarbons (PAHs) from bivalve samples (100 mg, dry weight). Additional clean-up and analyte enrichment was accomplished by in-tube solid-phase microextraction (SPME). For this purpose the extracts collected after MSPD were diluted with water and injected into a capillary column coated with the extractive phase. This capillary column was connected to the analytical column by means of a switching valve. Separation and quantification of the PAHs were carried out using a monolithic LC column and fluorescence detection. Since the in-tube SPME device allowed the processing …