Monochloroacetate, determination

Polymerization of 1,6-anhydro-/3-D-mannopyranose by means of monochloroacetic acid, using the conditions of Schuerch and coworkers,24 218 has also been accomplished,218 to give a polymannose in 25% yield. This polymer appears to be highly ramified and to contain a high proportion of terminal, nonreducing a-D-mannopyranosyl groups as determined by the precipitation reaction with concanavalin A (see Section IV,6). 

B) Ionization Constants. Determine the pH of 0.1 solutions of acetic, chloroacetic, and trichloroacetic acids. Convert the pH to hydrogen-ion concentration as moles per liter then calculate the ionization constants for acetic and monochloroacetic acid. 

Spectrophotometric determination of salicylic acid in aspirin was done by Wahbi et at. (20). A portion of powdered tablets or bulk aspirin powdered was extracted with ethanolic 1 % monochloroacetic acid. After filtration, the first derivative spectrum of the solution, was... 

Fig. 52. /[jm Re1/n characteristics for the reduction of H+ from a monochloroacetic acid system comprising an aqueous solution of 2 x 10-3M ClCH2COOH, 2 x 10 2M ClCH2COONa, and 1M NaCl. The points represent the behaviour determined experimentally by Bernstein and Vielstich [114], whilst the straight line represents the behaviour predicted for a kinetically stable species. 

Tokura et al.49 synthesized a polyamide of the Perlon type (40) starting from a 6-O-carboxymethyl-D-glucosamine derivative as monomer.This compound was obtained by carboxylmethylation of chitin with monochloroacetic acid, followed by hydrolysis of the glycosidic linkage. Hie molecular weight (Mw 15,000) of the resulting water-soluble polyamide 40 was determined by gel-permeation chromatography and electrophoresis (Scheme 11). 

Several reports concern the formation of organic ligand complexes of iron(iii). The variation of rate with ligand concentration in the reaction with mandelic acid > is interpreted as a pre-equilibrium ion-pair formation followed by dissociative complex formation within the ion-pair, rather than as simple 5 n2 formation. This interpretation is similar to that proffered for formation of malonate and oxalate complexes of chromium(iii) (see above). Rates of reaction of iron(iii) with a variety of phenols are all very similar, suggesting that iron(iii)-water bond breaking is rate determining here also. Sulphosalicylate reacts with FeOH + by the same rate-determining loss of water from the iron(m). Rates of formation of iron(iii) complexes with acetate, monochloroacetate, and propionate have been reported. ... 

It would presumably be possible to combine the last two methods to determine monochloroacetic acid and glycolic acid together. 

Where c, and are the concentrations of chloroform or monochloroacetic acid in the permeate, in the feed and the base concentration of the de-ionized (DI) water, respectively. Chloroform concentrations were determined using a total organic carbon (TOC) analyzer using the UV-persulfate method (Phoenix 8000, Rosemount Analytical Inc., Tekmar Dohrmann Division, Santa Clara, CA). Concentration of monochloroacetic acid was determined using a conductivity/TDS meter with RS232C (CON 110 series, Oakton Instruments, Vernon Hills, IL, manufactured by Eutech Instruments, Singapore). 

Three eoupons of carbonized membranes of final thickness 0.18 0.02 mm and carbonized at 400 °C for 4 h, were tested for the removal of chloroacetic acid. The PWP of the membranes at 1 psig were measured to be 5002 220 L/m h. All membranes were filtered with 100 mg/L of monochloroacetic acid (MCAA) and the rejection with volume of permeate collected was determined as shown in Fig. 8.42. 

Removal mechanism of the membranes can be explained as follows. The feed concentration in the dead end cell at the end of each experiment was measured and the concentration of monochloroacetic acid was determined. No change in concentration of the final feed compared with the initial feed concentration was noted in all the experiments. Accumulation of monochloroacetic acid on the feed side due to rejection or back difiusion would result in an increase in concentration of the feed at the end of the experiment. Given the large pore size of the membranes, approximately 0.3-0.44 pm, it was inferred that the removal of monochloroacetic add was due to its adsorption on the srrrface of the rtanolrbers rather than its rejection due to the size exclusiom... 

Cetinkaya, M., GC determination of monochloroacetic acid in surfactants and surfactant-containing body cleaning products (in German), Parfiim. Kosmet., 1991, 72, 816-818. 

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