Influence Of Extraction Procedure Research Articles

Authentication of Tonka beans extracts (Dipteryx odorata) using LC-UV/MS, GC-MS and multi element (13C, 2H and 18O) bulk specific isotope analysis

Tonka bean extract, prepared from Tonka beans, is mainly composed of Coumarin. However, due to alternative industrial procedure of production, different solvents and mixtures of solvents were tested for extraction. Investigation using HPLC-DAD-MS indicates influence of extraction procedure on compositions of main constituents. New polyphenols structures have also been found in extracts and improve the chemical analysis knowledge of these products. Waxes compositions using fatty acids methyl esters gas chromatography analysis have been determined and indicate important amounts of behenic and lignoceric acids. High polar constituents (sugars) were also pointed out with trimethyl silanization. As synthetic Coumarin addition represents the main adulteration, isotopic values of Tonka coumarin, isolated by crystallization, have also been determined using an elemental analyzer connected to an isotope ratio mass spectrometer (EA-IRMS). The δ13C values of authentic coumarin range from − 32.88 to − 31.38‰ for δ13C, between − 113‰ and − 83‰ for δ2H, and between 23.0 and 28.0‰ for δ18O. No isotopic effect was observed with different solvents extraction procedures, indicating that IRMS investigation of Coumarin is a powerful tool applied for naturalness control.

Influence of extraction procedures on phenolic content and antioxidant activity of Cretan barberry herb

The main goal of present study was the development, optimization and application of different extraction protocols, especially those employing green technologies, in order to obtain from Berberis cretica extracts with high antioxidant capacity. For this purpose, the applied methods: maceration, ASE and SFE coupled with ASE were incorporated. The antioxidant assessment was carried out using DPPH and total phenolic content (Folin–Ciocalteu) assays. Major constituents were elucidated using HPLC-DAD and UHPLC–HRMS/MS (hybrid IT-Orbital trap spectrometer) equipped with an ESI probe.The chromatographic and spectral data revealed the presence of several simple phenolic acids, derivatives of both caffeic and benzoic acids, and flavonoids in the produced extracts. It was clearly evidenced that the extraction method and solvents used affected both the activity and the chemical content of the results, significantly. The most beneficial conditions were calculated for methanol and water:ethanol (50:50) extracts derived from the combination of SFE and ASE methodologies. Obtained results classify Cretan barberry as a strong antioxidant agent.

Influence of extraction techniques on GC–MS screening results

Gas chromatography coupled with mass spectrometry (GC-MS) is often used as a confirmatory technique for positive results obtained with immunoassay screening tests, but it can also be used as a screening method in clinical and forensic toxicology. Because of different reasons (amount of sample available, urgency, cost of analysis, etc.), laboratory is often in position to perform just one extraction and screening per sample. Influence of different extraction procedures on results is usually overlooked, but it can have great impact on obtained results, both quantitatively and qualitatively. We prepared four different levels of commercial urine toxicology control samples Liquichek (BIO-RAD), containing 12 drugs-ofabuse using three different extraction procedures: liquid– liquid extraction system TOXI-TUBES A (VARIAN), liquid–liquid extraction system Chem Elut (VARIAN) and solid phase extraction system based on Amberlite XAD2 polymeric adsorbent columns (Sigma–Aldrich). All extracts were analyzed with GC-MS (SHIMADZU GCMS-QP5050A). Obtained results are presented and influence of extraction procedure on GC-MS screening results is evaluated for every extraction procedure.

Antioxidants from grape stalks and marc: Influence of extraction procedure on yield, purity and antioxidant power of the extracts

This study was aimed to assess the feasibility of extracting antioxidant compounds from wine-making wastes (grape stalks and marc) by solvent extraction. Together with the type of raw material it was also investigated the influence of some process parameters on final antioxidants yields and extract purity: a degreasing pre-treatment, type of solvent (ethanol or a mixture ethylacetate:water/9:1), temperature (28 or 60°C) and length of maceration (5 or 24h). Solvent and temperature were statistically influent (p<0.05), and the yields were higher with ethanol (but with lower purities) and at 60°C. Antioxidant power of the extracts was evaluated by different analytical methods. An accurate comparison of our data with many literature works about antioxidants recovery from different natural sources showed similar results and highlighted a general great variability in the extraction procedures.

The influence of extraction procedure on ion concentrations in sediment pore water

Sediment pore water has the potential to yield important information on sediment quality, but the influence of isolation procedures on the chemistry and toxicity are not completely known and consensus on methods used for the isolation from sediment has not been reached. To provide additional insight into the influence of collection procedures on pore water chemistry, anion (filtered only) and cation concentrations were measured in filtered and unfiltered pore water isolated from four sediments using three different procedures: dialysis, centrifugation, and vacuum. Peepers were constructed using 24-cell culture plates and cellulose membranes and vacuum extractors consisted of fused-glass air stones attached with airline tubing to 60-cc syringes. Centrifugation was accomplished at two speeds (2,500 and 10,000 g) for 30 min in a refrigerated centrifuge maintained at 4 degreesC. Only minor differences in chemical characteristics and cation and anion concentrations were found among the different collecting methods with differences being sediment-specific. Filtering of the pore water did not appreciably reduce major cation concentrations, but trace metals (Cu and Pb) were markedly reduced. Although the extraction methods evaluated produced pore waters of similar chemistries, the vacuum extractor provided the following advantages over the other methods: ease of extraction, volumes of pore water isolated, minimal preparation time, and least time required for extraction of pore water from multiple samples at one time.

Soil nitrogen fractions as influenced by sample preparation and extraction

In order to evaluate the influence of extraction procedure on extractable nitrogen (N) fractions, fresh as well as dried soil samples were extracted with CaCl2 at various temperatures (20,40,60, 80°C) for 30–120 minutes. Data obtained were compared with those from the electro‐ultra‐filtration (EUF) method. Increasing the drying temperature as well as the extraction temperature led to an increase in Norg content. The EUF and CaCl2‐method produced comparable results for all N‐fractions (NO3 ‐, NH4 +, Norg) when an extraction temperature of 80°C was applied for two hours. Data presented suggested that the Norg fraction represented mainly the microbial biomass and may thus be considered as being easily available to plants.

Influence of extraction procedure on size of free amino acid pool of heart muscle

More free leucine, isoleucine, methionine, and phenylalanine and possibly valine and tyrosine was extracted from frozen pulverized heart muscle by heating in water at 100°C followed by deproteinization with trichloroacetic acid at 0°C than when the powder was extracted with trichloroacetic acid at 0°C. The question of which procedure estimates the true pool of free amino acids in the tissue is discussed.

Pyridine nucleotides in the thyroid: III. A method for determination of oxidized and reduced diphosphopyridine nucleotides using 6-phospho-[I14C]-gluconate

Methods are presented for assay of micromicromolar quantities of oxidized and reduced NAD following synthesis to NADP utilizing excess ATP and NAD kinase (ATP:NAD 2′-phosphotransferase, EC 2.7.1.23). NADP+ is assayed by minor modifications of prior methodology in which the yield of 14CO2 is proportional to NADP+ when excess 6-phospho[I14C]gluconate and excess 6-phosphogluconate dehydrogenase (6-phospho-d-gluconate:NADP+ oxidoreductase, EC 1.1.1.44) are present. The reduced nucleotides are assayed in their oxidized state following reaction with excess α-ketoglutarate, NH4+ and glutamate dehydrogenase (l-glutamate:NAD+ (NADP+) oxidoreductase (deaminating), EC 1.4.1.3). The prior methodology for NADP+ assay has been modified, without any sacrifice to sensitivity, so that incubations can be performed in reduced volumes and at room temperature. These modifications have enabled the assay procedures to be performed in center wells, temporarily sealed in counting vials, thereby eliminating the time consuming step of hyamine transfer. Using these methods equivalent amounts of nucleotides per gram wet weight tissue were obtained with different amount of tissue extract. Recovery of internal standards was virtually complete. Values for a number of mammalian tissues, obtained by utilization of the present methodology, are presented and are similar to those previously reported. The influence of extraction procedure upon nucleotide concentration obtained in tissues is mentioned.