Procedure for extracts

Ionic associates (lA) of polyoxometalates (POMs) with threephenylmethane dyes remain as perspective analytical forms for the determination of some nonmetals including P(V), As(V) and Si(IV). Several reasons hinder to the improvement of analytical characteristics of these reactions. Separation of dye excess and its lA with reagent are most important Procedure for extractive separation is often timeconsuming, complex and does not allow complete separation from reagent excess. 

Using the best procedures during data acquisition produces spectra with the maximum available information content. Once spectra are recorded that contain the information that is sought using the best procedures for extracting the information from the data is important to maximize the value of the analysis. This section will consider the procedures for data acquisition and the extraction of various types of information available from the data. 

Since 1978, several papers have examined the potential of using immobilised cells in fuel production. Microbial cells are used advantageously for industrial purposes, such as Escherichia coli for the continuous production of L-aspartic acid from ammonium fur-marate.5,6 Enzymes from microorganisms are classified as extracellular and intracellular. If whole microbial cells can be immobilised directly, procedures for extraction and purification can be omitted and the loss of intracellular enzyme activity can be kept to a minimum. Whole cells are used as a solid catalyst when they are immobilised onto a solid support. 

The usual procedure for extracting the exchange current Io is then to measure qw (=AUwr) as a function of I and to plot lnl vs T w (Tafel plot). Such plots are shown on Figs. 4.11 and 4.12 for Pt and Ag catalyst electrodes. Throughout the rest of this book we omit the subscript "W" from r w and simply write q,... 

The metabolite will frequently be more polar than the initial substrate, so that specific procedures for extraction and analysis must generally be developed, and the pure compound must be available for quantification. 

Both multi-residue methods are presented in several parts, which separate general considerations from procedures for extraction, cleanup and determination/ confirmation. Whereas in EN 12393 several extraction and cleanup steps cannot be combined arbitrarily, the modular concept is utilized to a greater extent in EN 1528. In the latter standard, there is no limitation to the combination of several extraction procedures, mostly designed for different commodities, e.g., milk, butter, cheese, meat or fish, with different cleanup steps. Both standards, EN 1528 and EN 12393, do not specify fixed GC conditions for the determination and confirmation. All types of GC instruments and columns, temperature programs and detectors can be used, if suitable. 

The other extraction method is an SEE procedure, which is a much easier procedure for extracting the nonpolar chemicals compared with polar chemicals. 

Excellent reviews are available (3, 5, 17) on the procedures for extraction, bioassays and identification of allelopathic chemicals. 

More recently, some novel pressurised procedures for extraction of additives from polymers have been developed (Table 3.3). The principal objectives of all these techniques, such as SEE [89], MAE [90] and pressurised fluid extraction (PEE), is to replace the conventional extraction methods by shortening the extraction time, reduction in solvent use and automation. 

Sanchez-Ferrer A, Bru R and Garcia-Carmona F. 1989. Novel procedure for extraction of a latent grape polyphenoloxidase using temperature-induced phase separation in Triton X-114. Plant Physiol... 

Selmer and Sorenson [52] have described a procedure for extraction of ammonium from seawater for 15N determinations. In this method ammonium nitrogen was converted to indophenol and concentrated onto an octadecylsi-... 

Sibbesen E. A simple ion-exchange resin procedure for extracting plant available elements from soil. Plant Soil 1977 46 665-670. 

Christman et al. [72] gave details of procedures for extraction, clean-up, and concentration of samples of soil prior to the determination of their content of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans by gas chromatography and by gas chromatography-mass spectrometry. Instrumental parameters are also included. Some typical results are tabulated. 

Double-layer charging current and ohmic drop are likely to interfere at high scan rates. The procedures for extracting the Faradaic component of the current and correcting the potential axis from the effect of ohmic drop described earlier (see Sections 1.3.2 and 1.4.3) should then be applied. The same is true for the double-layer effect on the electron transfer kinetics (Section 1.4.2). 

Lopez-Avila V, Bauer K, Milanes J, et al. 1993. Evaluation of Soxtec extraction procedure for extracting organic compounds from soils and sediments. J AOAC International 76 864-880. 

A.V. Loskutov, C.W. Beninger, G.L. Hosfield and K.C. Sink, Development of an improved procedure for extraction and quantitation of safranal in stigmas of Crocus sativus L. using high performance liquid chromatography. Food Chem. 69 (2000) 87-95. 

The design procedure for extracting equipment requires the evaluation of the following ... 

Objective. To date, there is no simple or rapid procedure for testing PCBs in milk. Headspace solid-phase microextraction (HSSPME) is a promising approach, but only a few works have applied this technique to milk (1, 2). Here, we present a simple and rapid saponification-HSSPME procedure for extracting PCBs from milk. (119 words)... 

Suggest a suitable extraction procedure for extracting the analytes from the cream and for removing oily excipients and indicate any other preparation which might be required prior to analysis. 

Pectase was found in plants, both in soluble and non soluble form. It was able to break down pectose into pectinic acid, and was attributed some similarity to diastase. Neither materials could be crystallized (Payen, 1874). Claude Bernard was the first to show lipolytic activity in pancreas in 1856 (Tauber, 1949), and Dobell (1869) found that an extract from pancreas hydrolyzed both fat and starch he gave a procedure for extraction and stabilization and named this preparation pancreatine . 

Miller SA, Dykes DD, Polesky HF (1988) A simple saltung out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res 16 1215... 

Since interferences could not be adequately eliminated with the alumina column, Gissel and Schaal (611) proposed an alternative procedure for extract purification involving use of Kieselgel thin-layer chromatographic plates, elution with trichloroethane/ethanol (8 2), and detection at 254 nm. The detection limit for three thiouracil residues in thyroid glands was in the range 0.5-1.0 ppm. 

Procedures for extraction of chymosin from veils were described by Ernstrom and Wong (1974). Crude rennet extract contains active chymosin and an inactive precursor (prochymosin). Addition of acid to the extract facilitates conversion of prochymosin to chymosin and allows the extract to reach maximum activity. Even though activation at lower pH is faster, poor stability of chymosin below pH 5.0 in the pres-... 

This unit describes procedures for extraction, purification, and identification by MALDI-MS of fiavonol glycosides from a plant source. The extraction and purification protocols are not meant to be comprehensive, but rather to offer guidelines for sample preparation prior to a MALDI-MS analysis. The MALDI-MS technique is suggested as a complement to other analytical methods such as HPLC or NMR. Its strength lies in the ability to rapidly screen a number of samples for the presence of fiavonol glycosides, which can be identified on the basis of their molecular weights. 

The jack beans grown in Japan, Canavalia ensiformis var. gladiata, present special problems in the isolation procedure. Hanabusa (18) has proposed a modified procedure for extraction without the use of acetone. 

A procedure for extracting BHA and BHT from vegetable oils has been reported by Phipps (98). The oil was dissolved in n-heptane and extracted with dimethylsulphoxide (DMSO). Extracts of DMSO were mixed with aqueous sodium chloride solution, and the SPA were back-extracted into petroleum ether with subsequent concentration and analysis. 

Touillage or Detolitation (Fr). The procedure for extracting residual Tolite (TNT) for di- and tri-spent acids by means of mono-spent acid Ref Pepin Lehaiieur(1935), 174... 

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