RESIDUAL CONTENT

Industrial Hquid chlorine is routinely analy2ed for moisture, chlorine, other gaseous components, NCl, and mercury foUowing estabHshed procedures (10,79). Moisture and residue content in Hquid chlorine is determined by evaporation at 20°C foUowed by gravimetric measurement of the residue. Eree chlorine levels are estimated quantitatively by thiosulfate titration of iodine Hberated from addition of excess acidified potassium iodide to the gas mixture. 

DETERMINATION OF THE RESIDUAL CONTENTS OF CATIONIC FLOCCULANTS IN WATERS... 

Tetracycline antibiotics have found wide application in animal industries for treatment, preventive maintenance and stimulation of growth of large horned livestock owing to what their residue amounts can be present at milk and meat of animals. Residue amounts of antibiotics are not toxic, however, capable to cause allergic reactions and to promote development of tolerance of the some people pathogenic bacterias. According with the legislative requirements of a number of the European countries it is forbidden to deliver to the population production polluted residual contents of tetracyclines. 

Witrogen level veuies with crude source and residue content. 

FCC feedstocks contain sulfur in the form of organic-sulfur compounds such as mercaptan, sulfide, and thiophenes. Frequently, as the residue content of crude oil increases, so does the sulfur content (Table 2-5). Total sulfur in FCC feed is determined by the wavelength dispersive x-ray fluorescence spectrometry method (ASTM D-2622), The results are expressed as elemental sulfur. 

An algorithm for calculating the symmetrical (two-tailed) /-factors for p = 0.1 is incorporated its use corresponds to the statement that the probability that measurements on a future batch, given the linear trend already established, will inadvertently be found to be below the specification limits of Y% of nominal, at a shelf-life that would lead one to expect a residual content at or above the specification limit, is p = 0.05. ... 

Gavage dosing of male and female rats with endosulfan (65.3% a-endosulfan, 33.7% P-endosulfan) for 30 days resulted in a greater accumulation of endosulfan in fatty tissue from females than males (Dikshith et al. 1984). The authors speculated that the difference between males and females was a function of more rapid excretion of endosulfan by males than females, and that this could account for the higher sensitivity of female rats to endosulfan toxicity. However, excretion of endosulfan and its metabolites was not directly measured in this study therefore, alternative explanations for the differences in residue content and toxicity caimot be discounted. 

Acetic acid and 10, 15, or 20% acetyl chloride were fed as a mixture into a modified falling film micro reactor (also termed micro capillary reactor in [57]) at a massflow rate of 45 g min and a temperature of 180 or 190 °C [57]. Chlorine gas was fed at 5 or 6 bar in co-flow mode so that a residual content of only 0.1% resulted after reaction. The liquid product was separated from gaseous contents in a settler and collected. By exposure to water, acetyl chloride and acetic anhydride were converted to the acid. The hydrogen chloride released was removed. 

Tabb, D. L. Huang, Y. Wysocki, V. H. Yates, J. R. Influence of basic residue content on fragment ion peak intensities in low-energy collision-induced dissociation spectra of peptides. Anal. Chem. 2004, 76,1243-1248. 

Table 10. The residual content of persistent organochorine compounds in soils of nitrate biogeochemical province of the Desert region of biosphere, Uzbekistan, ppb.

Gahulin, R. V. (1994). Cartographic assessment of DDT residual contents state in agrolandscapes of the Mugano-Salyansk region (Azerbaijan). Agrochemistry 9, 124—130. 

In another study carried out by Biers et al (1994), the residual contents of intact Corinthian plastic vases of the 7-6th Centuries BC were analysed nondestructive by pouring solvent into the vessels and decanting. A large number of mono-, sesqui- and diterpenoids were identified in the solvent washes. The diterpenoid, manoyl oxide [Structure 7.15] was identified in 16 vases. This molecule is found in the bark of Pinus and Abies spp. and in the essential oils of the Cupressaceae family including Juniperus oxycedrus. 

Vinyl chloride monomer (VCM) is the main substrate for the manufacture of polymers used as packaging materials for food. Since VCM is considered by lARC to be a human carcinogen, monomer levels in PVC food packaging materials are strictly controlled. To ensure a safe product, the residual content of VCM in the finished material or article is limited to one mg per kg in the final product (Council Directive 78/142/EEC). Furthermore, VCM should not be detectable in foodstuflfs. Commission Directives 80/766/EEC and 81/432/ EEC give the method of analysis for official control of the VCM level in food packaging materials and in foods - gas-phase chromatography using the headspace method, after dissolution or suspension of samples in N,N-dimethylacetamide. Both residual monomer content of the polymer and... 

The residual content of immiscible liquids can be defined by the amount of NAPL remaining in the subsurface when pore geometry permits NAPL flow greater than the retention capacity. In an outdoor pilot experiment. Fine and Yaron (1993) studied the effect of soil constituents and soil moisture contents on the retention of kerosene in the subsurface. This retention is termed the kerosene residual content (KRC). Ten soils were studied, with a broad spectrum of clay and organic matter contents, together with four soil moisture contents corresponding to oven-dried, air-dried. 

Fig. 8.42 Kerosene residual content (KRC) of soils as a function of clay and moisture contents. Reprinted from Fine P, Yaron B (1993) Outdoor experiments on enhanced volatilization by venting of kerosene components from soil. J Contam Hydrology 12 335-374. Copyright 1994 with permission of Elsevier...

The extent of kerosene trapping was determined quantitatively in a series of laboratory and outdoor experiments with Swedish soils (Jarsjo et al. 1994), yielding an empirical equation for the kerosene residual content as a function of soil composition ... 

Most commercial products are mixtures because of the way they are manufactured. For instance many surfactant hydrophobes come from assorted products such as petroleiun alkylate cuts or triglyceride oils, with a molecular weight distribution that could be narrow or wide. Usually, a purification and separation of single isomeric species would be too costly and, in most cases, pointless. Moreover, the synthesis reactions involved in the surfactant manufacturing might be the intrinsic reason of the production of a mixture, such as in the case of polycondensation of ethylene oxide which results in an often wide spread ethylene oxide munber (EON) distribution. A residual content of some intermediates or by-products might also be a significant cause for mixture effects. 

The conditions under which the drug is used need to be estimated as do acceptable residues linked to the level of acceptable risk to the consumer. The acceptable level of risk, which is determined in theory at the risk management stage, has already been expressed in terms of residues by the ADI under hazard characterization. Moreover, the elements considered for hazard identification, hazard characterization, and exposure assessment make it possible, for a given form of utilization of a particular substance, to establish a profile of residues in animal tissues and to associate this with a profile of consumer exposure. Comparison of this consumer profile and ADI indicates whether the mode of utilization of the substance is acceptable or not. Analysis of the different results of residue content in animal products then provides an indication of level of residues in one or several animal tissues, making it possible to differentiate between veterinary drug applications that do or do not permit compliance with the ADI. 

The MRL values for muscle, liver, kidney, and fat are set in proportions that reflect the tissue distribution of the residues. To avoid producing a set of highly complex figures for different tissues and different animal species, the JECFA tries as far as possible to harmonize these values to keep their number down. When it appears that the residue contents in a given tissue are likely to be too small for the feasible control after a recommended withdrawal period of residue contents in other tissues, the JECFA likewise cannot propose any MRL for that particular tissue. 

The stability of SMZ residues in bovine and porcine tissue was evaluated. The residue content decreased similarly in the different types of samples to about 50% during frozen storage at — 20°C after 15 months. Storage at room temperature for 24 hours and at 20°C for 1 week did not affect the drug levels however, they decreased significantly when the sample had been stored for 1 month (180). 

Transferring and a decreasing profile of SQX in eggs was the aim of several studies (181,182). The drug content reached a plateau after 4 days of SQX feeding the residue content began to decrease 1 day after the withdrawal of dietary SQX. However, the disappearance profile in albumen was different from that in egg yolk. 

Many organochlorine pesticides (OCPs), which have shown undesirable effects in humans and the environment, have been banned in developed countries. Even so, OCPs deserve particular attention, for they are very stable and can accumulate in food chains (9). Products of animal origin as well as human mother s milk almost always contain residues of organochlorine compounds. The residue content of this milk is 10-30 times higher than that of cow s milk (10,11). 

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