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EN
The second part of the review shifts attention to novel modern materials applied to dSPE as sorbents, that are often designed specifically for the extraction of a particular analyte. This part will focus on advances in materials such a molecularly imprinted polymers (MIP), metallic organic frameworks (MOF), layered double hydroxides (LDH) or magnetic nanoparticles (MNP). As in the first part, studies chosen for this review will be listed in tables alongside their relevant validation parameters at the end of each chapter. Studiesfound to be particularly interesting due to high effectiveness, unusual operating procedure or scope, among other reasons, will be described in greater detail.
EN
Solid phase extraction (SPE) is an analytical procedure developed with the purpose of separating a target analyte from a complex sample matrix prior to quantitative or qualitative determination. The purpose of such treatment is twofold: elimination of matrix constituents that could interfere with the detection process or even damage analytical equipment as well as enriching the analyte in the sample so that it is readily available for detection. Dispersive solid phase extraction (dSPE) is a relatively recent development of the standard SPE technique that is attracting growing attention due to its remarkable simplicity, short extraction time and low requirement for solvent expenditure, accompanied by high effectiveness and wide applicability. There is an enormous abundance of articles concerning advances in sample preparation and analysis published every year. The aim of this review is to bring to closer attention developments of materials with potential application as sorbents in dSPE technique through a thorough survey of recently conducted analytical studies focusing on methods utilizing novel, interesting nanomaterials in dSPE procedures and evaluation of their performance and suitability based on comparison of provided validation parameters with previously reported analytical procedures. The first part of this review focuses on widely known and utilized materials such as silica and carbon and their modifications, up to and including graphene and carbon nanotubes. Studies chosen for this review will be listed in tables alongside their relevant validation parameters at the end of each chapter. Applications found to be particularly interesting due to high effectiveness, unusual operating procedure or scope, among other reasons, will be described in greater detail.
EN
The sample preparation stage is a critical step in the whole analytical procedure as it often determines the efficiency of the process. What is particularly noticeable in the area of biological samples. Blood, milk, urine, saliva or tissue are only few examples of complicated biological matrix, that require a optimization of sample pre-treatment method for particular analytes. For these purpose, the aim of following chapter was to characterized main problems with sample preparation method as well as highlighted some innovative ways how to improve sample preparation stage. Attention was particularly focused on the use of dispersive solid phase extraction (dSPE), which has achieved high growth in interest in recent years, mainly due to the simplicity and rapidity of performance. This method is not only used with commercially available sorbents, but also provides a basis for trying to apply new analytical tools for separation of analytes from matrix. Following the trends of nanotechnology and within the rules of green analytical chemistry, scientists are facing the challenges of determining and identifying compounds from various chemical groups. Frequently targeting analytes at trace concentration levels as well biological samples. In addition, attention is also focused on reagents reduction and shorter analysis time but also in terms of minimization of sample volume, which should to be collected. Herein the chapter presented describes exemplary new proposals in sorbents such as molecularly imprinted polymers (MIPs), supported ionic liquids (ILs), dendrimers and metal-organic framework (MOFs). In addition, it also looked at the potential use of magnetic nanoparticles as carriers. New sorbents in sample preparation together with modem instrumental techniques therefore allow the development of a procedure that will be characterized by high selectivity and specificity.
EN
In this study, single-walled carbon nanotubes (SWNTs) were used to determine organochlorine pesticides (chlorothalonil and pentachloronitrobenzene) in water using dispersive solid-phase extraction (DSPE), followed by gas chromatography (GC). The optimal adsorption conditions were determined by analyzing the effect of adsorbent dosage, adsorption time, eluent type and volume, and elution time. Under the optimal conditions, a good linearity was obtained at concentrations from 10 to 400 μg L−1 with correlation coefficients ranging from 0.9991 to 0.9986. The limits of detection (LOD) for the two organochlorine pesticides were 0.025 and 0.049 μg L−1, and the limits of quantification (LOQ) were 0.080 and 0.156 μg L−1, respectively. The accuracy of the proposed method was evaluated by measuring the recovery of the spiked samples, which ranged from 82.5% to 110.5% at spiking levels of 0.5–10 μg L−1 with relative standard deviations lower than 5.6% (n = 6). This method was successfully applied to determine the target analytes in canal water, drinking water, and water taken from the inlets and outlets of a wastewater treatment plant. The results demonstrate that the developed method has great potential for determining the two organochlorine pesticides in water samples.
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