Residues, determinations using

Microcarbon residue the carbon residue determined using a themogravimetric method. See also Carbon residue. 

Michulec, M. and W. Wardencki. 2005. Selected aspects of chromatographic solvents residues determination using HS, SPME an SDE techniques for isolation and preconcentration of analytes. Book of abstracts of 11th International Symposium on Separation Sciences, September 12-14, 2005, Pardubice, Czech Republic. 

Table 22.4. Hydrogen-bond lengths for some polypeptides and copolypeptides incorporated with Gly residues determined using Equations (22.1) and (22.2) through the observation of chemical shift tensor components 622 and isotropic chemical shift...

Using the equilibrium equations of the elasticity theory enables one to determine the stress tensor component (Tjj normal to the plane of translumination. The other stress components can be determined using additional measurements or additional information. We assume that there exists a temperature field T, the so-called fictitious temperature, which causes a stress field, equal to the residual stress pattern. In this paper we formulate the boundary-value problem for determining all components of the residual stresses from the results of the translumination of the specimen in a system of parallel planes. Theory of the fictitious temperature has been successfully used in the case of plane strain [2]. The aim of this paper is to show how this method can be applied in the general case. 

The quantity of undrainable residual moisture caimot be predicted without the benefit of experimental data. Equation 17 (6) indicates the important parameters where the exponents were determined using limited experimentation. Introducing the approximation that is proportional to 1/d, where s is the specific surface area per weight of solid, the modified equation for undrainable liquid becomes... 

J. Cai and J. Henion, Quantitative multi-residue determination of /3-agonists in bovine urine using on-line immunoaffinity extr action-coupled column packed capillary liquid cliromatogr aphy-tandem mass spectr ometry , 7. Chromatogr. 691 357-370 (1997). 

This photoelastic stress analysis is a technique for the nondestructive determination of stress and strain components at any point in a stressed product by viewing a transparent plastic product. If not transparent, a plastic coating is used such as certain epoxy, polycarbonate, or acrylic plastics. This test method measures residual strains using an automated electro-optical system. 

The lyophililized intestinal contents or faeces were treated for enzyme inactivation in 5 ml 96 % EtOH for 20 min at 75-80 °C. After addition of 5 ml water the mixture was stirred 30 min and centrifuged at 6000 g also for 30 min. In the supernatant galacturonan was estimated by the m-hydroxydiphenyl (MHDP) reaction [7] and OligoGalA were determined using HPTLC. In the dried residues, the content of galacturonan and the DE were estimated after extraction with 0.5 % EDTA. 

If the relevant residue cannot be properly determined using a routine multi-method, an alternative method must be proposed. In the case of residues consisting of a variety of structurally related compounds, a common moiety method may be acceptable in order to avoid the use of an excessive number of methods for individual substances. For example, the relevant residue of isoproturon in plant material is defined as the sum of isoproturon and all metabolites containing the 4-isopropylaniline group. Therefore, residues are determined following hydrolysis as 4-isopropylaniline and are expressed as 4-isopropylaniline equivalents. It is not necessary to validate the method individually for all possible metabolites which are covered by the residue definition (e.g., all metabolites which contain the 4-isopropylaniline group), provided that it is demonstrated that in the first step, the conversion to the common moiety is complete. However, common moiety methods often lack sufficient specificity, and should therefore be avoided if possible. If need be, their use must be justified. 

The method must be capable of determining all components (a.i. and relevant/major metabolites) that are included in the residue definitions used in the assessment of risk to nontarget organisms. For ground (drinking) water and air, the risk to con-sumers/operators or bystanders must also be considered. 

The target number of commodity samples to be obtained in the OPMBS was 500, as determined using statistical techniques. A sample size of 500 provided at least 95% confidence that the 99th percentile of the population of residues was less than the maximum residue value observed in the survey. In other words, a sample size of 500 was necessary to estimate the upper limit of the 95% confidence interval around the 99th percentile of the population of residues. 

For FL detection, maximum emission and excitation wavelengths are determined using a fluorimeter. Stoev used fluorescence detection to analyze for closantel (excitation at 335 nm, emission at 510 nm) residues in animal tissue. 

The residue levels of 46 pesticides, including oxyfluorfen in soil, were determined using GC/ITDMS as described in S ection 3.2.1. The conditions for GC/ITDMS were as follows column, fused-silica capillary (30 m x 0.25-mm-i.d.) with a0.25- am bonded phase ofDB-5 column temperature, 50 °C (1 min), 30 °Cmin to 130 °C, 5 °C min to 270 °C inlet and transfer temperature, 270 and 220 °C, respectively He gas with column head pressure, 12psi injection method, splitless mode. The retention time and quantitation ion of oxyfluorfen were 23.9 min and mjz 252, respectively. ... 

For air analysis, a known volume of air is passed through a sampling cartridge for a preset period of time. The cartridge is eluted with methanol and reduced to dryness prior to reconstitution of the residue in 10 mL of water-ACN-85% phosphoric acid (700 300 1, v/v/v) solvent mixture. Residue determination is carried out using HPLC/UV at 280 nm. 

A 50-g soil sample is homogenized with 200 mL of water (if the solution pH is <6, adjust to pH 6-8 using 1M NaOH). A 100-mL aliquot portion of the soil/water supernatant is extracted with a 2-g Cig cartridge followed by a 5-g Cig cartridge and the eluate is evaporated to dryness. The residue of trinexapac is dissolved in 4 mL of water-phosphate buffer (pH 7)-ACN-TBABr (90 5 5 0.3). Residue determination is performed using HPLC/UV with a two-column switching system. 

Clark-Lewis I, Schumacher C, Baggiofini M, Moser B. Structure-activity relationships of interleukin-8 determined using chemically synthesized analogs. Critical role of NH2-terminal residues and evidence for uncoupling of neutrophil chemo-taxis, exocytosis, and receptor binding activities. J Biol Chem 1991 266 23128-34. 

HS-GC methods have equally been used for chromatographic analysis of residual volatile substances in PS [219]. In particular, various methods have been described for the determination of styrene monomer in PS by solution headspace analysis [204,220]. Residual styrene monomer in PS granules can be determined in about 100 min in DMF solution using n-butylbenzene as an internal standard for this monomer solid headspace sampling is considerably less suitable as over 20 h are required to reach equilibrium [204]. Shanks [221] has determined residual styrene and butadiene in polymers with an analytical sensitivity of 0.05 to 5 ppm by SHS analysis of polymer solutions. The method development for determination of residual styrene monomer in PS samples and of residual solvent (toluene) in a printed laminated plastic film by HS-GC was illustrated [207], Less volatile monomers such as styrene (b.p. 145 °C) and 2-ethylhexyl acrylate (b.p. 214 °C) may not be determined using headspace techniques with the same sensitivities realised for more volatile monomers. Steichen [216] has reported a 600-fold increase in headspace sensitivity for the analysis of residual 2-ethylhexyl acrylate by adding water to the solution in dimethylacetamide. 

Since equal numbers of disordered and ordered residues were used for training and testing, prediction success would be about 50% if disordered and ordered sequences were the same. In contrast to this 50% value, prediction success rates for the short, medium, long, and merged datasets were 69% 3%, 74% 2%, 73% 2%, and 60% 3%, respectively (Romero et al., 1997b), where the standard errors were determined over about 2200, 2600, 2000, and 6800 individual predictions, respectively. 

A wide variety of methods have been developed for the detection of residual monomers in polymeric materials. Volatile monomers, for example, acrylonitrile, butadiene, vinyl chloride, etc., are normally determined using headspace GC methods. 

A 10 g sample is roasted at 650°C and decomposed with hydrochloric acid/hydrogen peroxide. The Pt and Pd in the solution is pre-concentrated using adsorbent materials which are composed of active charcoal and anion resin. The adsorbent materials are washed sequentially with 2% ammonium bifluoride, 5% hydrochloric acid and distilled water, and subsequently ashed in a muffle furnace at 650°C. The total residue of ca. 0.25 mg is dissolved with 2 ml fresh aqua regia, then diluted to 5ml using 10% hydrochloric solution, and determined using ICP-MS, which has a detection limit of 0.2 ppb for Pt and Pd. The residue can also be mixed with a spectral buffer, and determined by DC-arc ES, which has detection limits of 0.3 ppb for Pt and 0.2 ppb for Pd. 

Carbon turnover in production fields can be determined, using non-isotopic techniques, by combining historical soil samples, current soil samples, and whole field yield monitor data. Sensitivity analysis of such data shows that the amount of above-ground biomass that could be harvested decreases with root to shoot ratio (Table 8.1). For example, if root biomass is ignored, analysis suggests that only 20-30% of the above-ground biomass can be harvested, whereas if the root to shoot ratio is 1.0, then between 40% and 70% of the residue could be harvested. 

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