Effectiveness chloride extraction

The reaction is a sensitive one, but is subject to a number of interferences. The solution must be free from large amounts of lead, thallium (I), copper, tin, arsenic, antimony, gold, silver, platinum, and palladium, and from elements in sufficient quantity to colour the solution, e.g. nickel. Metals giving insoluble iodides must be absent, or present in amounts not yielding a precipitate. Substances which liberate iodine from potassium iodide interfere, for example iron(III) the latter should be reduced with sulphurous acid and the excess of gas boiled off, or by a 30 per cent solution of hypophosphorous acid. Chloride ion reduces the intensity of the bismuth colour. Separation of bismuth from copper can be effected by extraction of the bismuth as dithizonate by treatment in ammoniacal potassium cyanide solution with a 0.1 per cent solution of dithizone in chloroform if lead is present, shaking of the chloroform solution of lead and bismuth dithizonates with a buffer solution of pH 3.4 results in the lead alone passing into the aqueous phase. The bismuth complex is soluble in a pentan-l-ol-ethyl acetate mixture, and this fact can be utilised for the determination in the presence of coloured ions, such as nickel, cobalt, chromium, and uranium. 

Dermatitis-producing effect. Fruit-fixed oil, applied externally to adults at an undiluted concentration, was active ". Diuretic activity. Decoction and infusion of the dried leaf, administered orally to adults at a dose of 5 mL/person for 20-25 days, increased daily urinary output by 100-145 mL, and did not affect blood/sodium, potassium, and chloride " . Ethanol (50%) extract of the fresh leaf, administered intragastrically to rats at a dose of 40 mL/kg, was active. Five parts of fresh plant material in 100 parts water/ethanol was used "". The extracts of leaves of three isolates—GO, AO, and CT—administered to Dahl salt-sensitive, insulin-resistant rats at a dose of 60 mg/kg for 6 weeks, were active . DNA-binding effect. Methanol extract of dried leaves and twigs, at a concentration of 1 pg/mL, was inactive "". ... 

Cytotoxic activity. Ethanol (90%) extract of the dried entire plant, in cell culture at a concentration of 0.25 mg/mL, was active on human lymphocytes Veto cells, effective dose (EDljo 0.36 mg/mL Chinese hamster ovary cells, EDjo 0.44 mg/mL and Dalton s lyphoma, EBj LZ mg/mL . Methylene chloride extract of the dried leaf, in cell culture, produced weak activity on CA-colon-SW 480, inhibitory concentration (IO506.I p,g/mL. A concentration of 500 ppm was inactive on CA-human-colon-CO-115 . Methylene chloride extract of the dried root, in cell culture at a concentration of 500 ppm, was inactive on CA-human-co-lon-CO-115 and active on CA-colon-SW 480, IC50 3.6 p-g/mL. Methanol extract of the dried root, in cell culture at a concentration of 500 ppm, was inactive on CA-colon-SW 480 and CA-human-colon-CO-115 . Ethanol (50%) extract of the seed, in cell culture, was inactive on CA-9KB, ED50 greater than 20 pg/mL 5 Water extract of the dried seed, in cell culture at a concentration of 500.0 pg/mL, produced weak activity on CA-mammary-microal-veolar . Water extract of the dried seed, in cell culture at a concentration of 500 pg/ mL, was inactive on CA-JTC-26 . Seed oil, in cell culture at concentrations of 0.01% and 0.1%, was inactive on the rat fibroblasts. A concentration of 1% produced weak activity " " . Seed oil, in cell culture at... 

The same statistical procedures were used here to evaluate the effects of humics on batch and continuous LLE. A base extraction procedure (19) was required for processing methylene chloride extracts prior to GC injection in order to protect the GC column from contamination by humics. This process led to losses of 2,4-dichlorophenol and the chlorinated biphenyls. Therefore, these compounds were not used in the evaluation of the CLLE in the presence of humics. All other compounds were not affected by the base extraction procedure. The ANOV procedure tested each compound for changes in concentration by comparing early batch extraction recoveries (from freshly prepared solution) to later ones (after the 12.5-L extraction). This process was done separately for Parts 1 and 2. It was therefore possible to test each compound for time-dependent decreasing concentration with and without the presence of humics. 

Iindau and Spalding [21] have studied the effects of 2 M potassium chloride extractant ratios of between 1 1 to 1 10 on nitrate recovery in nitrate and nitrite extractions from soil. Preliminary data indicated that concentrations of extractable nitrate and nitrogen isotopic values were influenced by the volume of extractant. The 1 1 extractions showed decreasing nitrogen isotope values with increasing nitrate levels, whereas in the 1 10 extractions these values were independent of each other. Incomplete extraction occurred for the 1 1 ratios. The ratio required for maximal recovery was not determined. 

Solvent selection depends largely on the nature of the analytes and the matrix. Although the discussions in Chapter 2 can be used as a guideline to account for the solvent-analyte interactions, the matrix effects are often unpredictable. There is no single solvent that works universally for all analytes and all matrices. Sometimes, a mixture of water-miscible solvents (such as acetone) with nonmiscible ones (such as hexane or methylene chloride) are used. The water-miscible solvents can penetrate the layer of moisture on the surface of the solid particles, facilitating the extraction of hydrophilic organics. The hydrophobic solvents then extract organic compounds of like polarity. For instance, hexane is efficient in the extraction of nonpolar analytes, and methylene chloride extracts the polar ones. 

Add 10 mL of 95% ethanol and heat almost to boiling for 5 min on a steam bath with stirring. Then filter the hot mixture on a small Hirsch funnel. Scrape out the test tube with a spatula, let the tube drain thoroughly, and squeeze liquid out of the solid residue in the funnel with a spatula. Pour the yellow filtrate into a 125-mL Erlenmeyer flask. Then return the solid residue, with or without adhering filter paper, to the original test tube, add 10 mL of dichloromethane to effect an extraction, insert the condenser, and reflux the mixture for 3-4 min. Filter the yellow fitrate and add the filtrate to the storage flask. Repeat the extraction with two or three further 10-mL portions of dichloromethane, pour the combined extracts into a separatory funnel, add water and sodium chloride solution (to aid in layer separation). 

The analysis of simple fulminate-chlorate mixtures may be effected by extraction either with water or with pyridine. In the former method the mixture ts digested with c

mercury fulminate is dried at 50 for three hours and weighed. Some fulminate dissolves in the water. This is estimated by precipitation as sulphide. The chlorate may also be determined in the filtrate. The solution t boiled with nitric acid and tlwn treated with fbrntaldehyde and silver nitrate. Silver chloride is precipitated and the estimation may be made gravimetrically or by Vol hard s method. 

The following results illustrate the effect of yew extracts on taxoid titers. Initial studies involved T.andreanae and continued with P. raistrickii H10BA2. Table 5 shows the results of several different experiments in which T. andreanae was grown with either 1% or 1.5 % yew broth in the medium. Experiment 5-39 titers are from the methylene chloride extracts of the fungal broth of T. andreanae. Experiments 5-2,5-3, and 5-22 show the combined methylene chloride extracts of the broth, freeze dried extracts, and mycelial extracts. Blanks are uninoculated broths... 

An extractant composed of the quaternary amine and dinonyl naphthalenesulfonic acid was chosen for further process development it is prepared by mixing the sulfonic acid with methyl tricaprylyl amine chloride [MT(OD)A, Aliquat-336 from Henkel, and washing with water to remove the HCl from the organic phase. This extractant shows sufficient capacity and good reversibility (see curve B in Fig. 17). An increase of the extractant concentration from 0.25 to 0.31 M and to 0.50 M increases the capacity proportionally. At the elevated temperature chosen for the process (about 80°C) the viscosity of the 0.50 M extractant is acceptable. Elevation of the temperature from 22 to 88°C has only a small effect on extraction efficiency. 

Trials. The effectiveness of chloride extraction depends on characteristics of individual structures, such as the concrete composition, the actual chloride-penetration profile and the depth of cover. So, it may be useful to carry out a trial on an area (about 1 to 10 m ), which must be representative of the structure to be treated and should last at least 4 to 8 weeks. The results of such a trial in terms of the chloride profile before, during and after chloride extraction gives an indication of the duration required and can be used to show that chloride-extraction treatment of the particular structure will be effective under field conditions. Trials are most certainly recommended if prestressed structures are to be treated with chloride extraction. Careful monitoring of the potential of the prestressing steel should be carried out to establish the risk of hydrogen embrittlement. As a safe criterion, the potential should not become more negative than -900 mV SCE, as apphes for cathodic protection [13]. 

Side effects. During chloride extraction, hydroxyl ions are formed around the reinforcing steel, locally increasing the pH and sodium and potassium ions are enriched around the steel. These changes might stimulate aUcah-silica reaction (ASR, Section 3.4). In the framework of COST 521, the possibility of ASR was checked as a side-effect of chloride extraction [28,36,80,81]. The aggregates studied were reactive and the alkali content of the cement was just below the critical values. The results obtained with non-carbonated concrete showed that, under the worst conditions, chloride extraction induced concrete expansion, but no cracking was observed. 

L. Bertolini, C. L. Page, W. Y. Shu, Effects of electrochemical chloride extraction on chemical and mechanical properties of hydrated cement paste . Advances in Cement Research, 1996, 8, 93-100. 

Electrochemical treatments - cathodic protection, electrochemical chloride extraction and electrochemical realkalization are designed to shift the potential of the steel. This effect may be permanent in the case of cathodic protection or temporary but quite long term in the case of the other two techniques. 

Sohanghpurwala, A.A. (2003). Long-Term Effectiveness of Electrochemical Chloride Extraction on Laboratory Specimens and Reinforced Concrete Bridge Components. NACE Corrosion 2003. Paper No. 3293. 

The advantage of calcinm nitrite is that it can be added to the mix and has no serions effects on the design, construction and performance of the strnctnre other than its effect as a set accelerator. Mix design may require adjusting to include a retarder. Its disadvantage is that there mnst be enough to stop corrosion and it is consnmed with its exposure to chlorides. It is therefore important to calcnlate the chloride exposure for the life of the structure and add snfficient inhibitor. It does not inhibit the application of cathodic protection or chloride extraction in later life of the strnctnre if necessary. 

Following the trend of using PVC as matrix, research on the use of EFB as composite in PVC matrix was also reported. Bakar et at [37] used the EFB as filler in unplasticized poly(vinyl chloride) (PVC-U). They studied the effects of extracted EFB on the processability, impact and flexural properties of EFB/PVC-U composites. PVC-U resin, EFB and other additives were first dry-blended using a heavy-duty laboratory mixer and then milled into sheets on a two-roll mill before being hot-pressed and cut into impact and flexural test specimens. There were two kinds of EFB used in this experiment, which were extracted and xmextracted. The FTIR showed that the unextracted EFB contained oil residue, while the extracted one contained less oil residue. The results showed that both extracted and unextracted EFB decreased the fusion time and melt viscosity. However, the fusion time increased with the increase of extracted EFB content. Meanwhile, there was no significant difference in both the impact and flexural properties of extracted and xmextracted EFB. 

The results show that the three ligands (3,5,7) are quite effective in extracting divalent cations (except magnesium) from water to methylene chloride. The most effective seems to be the tetraacid (3) which extracts lead almost... 

Paraquat and diquat extracted from high-moisture crops were analyzed on a silica column (A = 257nm for paraquat and 310nm for diquat). A 40/60 acetonitrile/ water (5.0g NaCl to pH 2.2 with HCl) mobile phase was used [998]. The use of methanol in place of acetonitrile produced very broad and tailed peaks. A comparison of this separation was made with a separation system that consisted of an aminopropyl column and a ternary acetonitrile/methanol/water (NaCl/HCl system) mobile phase. The latter system took >2 hours to equilibrate, whereas the silica system was ready for use in 15 min. A plot of k versus percent acetonitrile (from 10% to 70%) was U-shaped and excessive peak tailing occurred at levels of <30% and >i50% acetonitrile. The authors make a special note that they minimized the NaCl/HCl concentrations used because of the corrosive effects chloride salts and acids have on LC hardware. Detection limits of lOppb and linear working ranges from 2 to 500 ng injected were reported. 

If the additive can be extracted in pure form from the polymer, both identity and concentration can be determined. After evaporation of the solvent IR, NMR or MS can be used to identify the additive. If quantitative analysis is desired, the sample should be finely divided and multiple extractions performed. A Soxhlet extraction apparatus is useful. If the identification technique indicates that more than one additive is present, further separation will be necessary. The use of another extracting solvent may be effective. For example, a methylene chloride extract which has been dried on a watch glass can be rapidly tested using a small amount of a different solvent. Hexane will remove aUphatic additives and leave behind the more polar materials. Table 3 lists some appropriate solvents. 

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