Hair alkaline hydrolysis

The most successful of these products contain high ratios of VP to DMAEMA and are partially quatemized with diethyl sulfate (Polyquaternium 11) (142—144). They afford very hard, clear, lustrous, nonflaking films on the hair that are easily removed by shampooing. More recendy, copolymers with methyl vinyl imidazoliiim chloride (Polyquaternium 16) (145) or MAPTAC (methacrylamidopropyltrimethyl ammonium chloride) (Polyquaternium 28) have been introduced. Replacement of the ester group in DMAEMA with an amide analog as in Polyquaternium 28 results in a resin resistant to alkaline hydrolysis and hence greater utility in alkaline permanent-wave and bleach formulations (see Quaternary ammonium compounds). 

The GC/MS procedures for methamphetamine are described in Table 4. The papers published in Japanese - have corresponding reports in English. - - Methamphetamine was detected and determined by mass fragmentography in rat hair after administration of the substance. Nine methods also detected the metabolite amphetamine or amphetamine alone. Suzuki et al. determined methamphetamine also in nail, sweat and saliva. The workup (EX after acid or alkaline hydrolysis) and derivatization technique (methanol-trifluoroacetic acid [TEA]) is rather uniform in most procedures. Nakahara et al. ° used methoxyphenamine excretion into beard hair to discuss several washing procedures. Alkaline or methanolic extraction are used with one exception. Derivatization is mainly made by fluorinated anhydrides. A review ° gives details on analytical procedures, incorporation rates of amphetamines from blood to hair, and relationship between drug history and drug distribution in hair. 

Human hair (congener specific) Ultrasonic extraction with acetone/hexane wash of extract with concentrated sulfuric acid and alkaline hydrolysis cleanup on Florisil column fractionation on carbon column HRGC/ECD No data No data Zupancic-Kralj et al. 1992... 

Reese and Eyring [45] have demonstrated that the reaction of sulfite with hair is a pseudo-hrst-order reaction. In other words, the chemical reaction of sulfite with the disulfide bond of hair is slower than diffusion of sulfite into hair. Elsworth and Phillips [46, 47] and Volk [48] examined the sulfi-tolysis of keratin, demonstrating that the rate of cystine cleavage is optimal at acid pH. Wolfram and Underwood [49] found a broad optimum for cystine cleavage by sulhte at pH 4 to 6. The decrease in cystine cleavage at acidic pH (below pH 4) is due to a decrease in the concentration of the nucleophilic sulhte species. On the other hand, the decrease in cystine cleavage as pH is raised (alkaline pH) results from alkaline hydrolysis of the Bunte salt [50]. 

Keratin is more sensitive to alkaline hydrolysis than to acid hydrolysis, making this determination more difficult and complicated. Sagal [109] has shown a higher uptake of alkali in bleached hair and in permanent-waved hair than in cosmetically unaltered hair. This effect could be due to a larger number of acidic sites however, it is more likely due to an increased susceptibility to hydrolysis for damaged hair. 

The acid decomposition method is generally used for the elementary analysis of human hair [50] alkaline hydrolysis can also be used [51], but rarely is, for the detection of inorganic elements. 

Ill The monoalkyl s. are gaining importance as dermatologically suitable - surfactants and emulsifiers in cleaners, in - skin preparations, and in - hair preparations due to their detergency and foaming behavior. Because of their sensitivity to alkaline hydrolysis, they are not used in detergents. They are also used as poljmierization emulsifiers (- polymerization additives). 

Hydrolysis of peptide and amide linkages is also a possible complication in an alkaline medium. Hydrolysis of the amide groups of the residues of aspartic and glutamic acids will increase the ratio of acidic to basic groups in the fibers, conceivably altering the isoelectric and/or isoionic points of the hair. 

Since the bleaching of human hair is carried out in an aqueous alkaline oxidizing medium, hydrolysis of the cystine oxide intermediates (Figure... 

CAS 96690-41-4 EINECS/ELINCS 306-235-8 Synonyms Hydrolyzed sericin Hydrolyzed silk protein Protein hydrolysates, silk Silk hydrolysate Silk, hydrolyzed Definition Hydrolysate of silk protein derived by acid, alkaline, or enzymatic hydrolysis Uses Antistat, humectant, emollient, moisture binder, substantivity agent for hair car, skin care... 

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