Hexadecyltrimethylammonium chloride

Surface heterogeneity may be inferred from emission studies such as those studies by de Schrijver and co-workers on P and on R adsorbed on clay minerals [197,198]. In the case of adsorbed pyrene and its derivatives, there is considerable evidence for surface mobility (on clays, metal oxides, sulfides), as from the work of Thomas [199], de Mayo and co-workers [200], Singer [201] and Stahlberg et al. [202]. There has also been evidence for ground-state bimolecular association of adsorbed pyrene [66,203]. The sensitivity of pyrene to the polarity of its environment allows its use as a probe of surface polarity [204,205]. Pyrene or ofter emitters may be used as probes to study the structure of an adsorbate film, as in the case of Triton X-100 on silica [206], sodium dodecyl sulfate at the alumina surface [207] and hexadecyltrimethylammonium chloride adsorbed onto silver electrodes from water and dimethylformamide [208]. In all cases progressive structural changes were concluded to occur with increasing surfactant adsorption. 

Van Ginkel CG, JB van Dijl, AGM Kroon (1992) Metabolism of hexadecyltrimethylammonium chloride in Pseudomonas strain Bl. Appl Environ Microbiol 58 3083-3087. 

Alkyltrimethylammonium surfactants, such as hexadecyltrimethylammonium chloride (HTAC) [6, 9, 38-41], hexadecyltrimethylammonium hydroxide (HTAH) [38, 42], hexadecyltrimethylammonium bromide (HTAB) [43-46], te-tradecyltrimethylammonium bromide (TTAB) [47], pentadecyltriethylammon-... 

Nitrodiphenyl phosphate (195) in aqueous micellar hexadecyltrimethylammonium chloride (CTAC1) in phosphate buffer at pH 8 is cleaved by l,3-dihydro-l-oxido-3-methyl-l,2,3-benziodoxaphosphole 3-oxide (196) and by I -//-1-oxido-5-methyl-1,2,3-benzodoxathiole 3,3-dioxide (197) 167 (196) and (197) were about 50 times less reactive towards o-iodosobenzoate (198). 

As an example we show in Fig. 2.13 measurements by Brun et al.43) using a cation exchange electrode. Larsen et al.44,4S) used bromide and chloride specific electrodes for solubilization studies in 0.1 M hexadecyltrimethylammonium chloride or bromide solutions, 76-77% of the counterions are bound, a figure changing only slightly... 

Transamination. Transamination with pyridoxal or analogs requires a metal catalyst such as Cu(II). However, transamination can be effected with DPL in combination with hexadecyltrimethylammonium chloride. By using these two reagents phenylglycine undergoes transamination with 2-oxoglutaric acid (equation I). 

Mullins and Kirkbright (38) reported separation of the UV absorbing anions iodate, nitrite, bromide, nitrate and iodide using a micellar mobile phase containing hexadecyltrimethylammonium chloride above its CMC. Figure 2 illustrates this separation with two different concentrations of micellar reagent. Increasing the concentration of hexadecyltrimethylammonium chloride decreases the retention time (38) on the column. 

The decrease in retention of the anions as the concentration of hexadecyltrimethylammonium chloride is increased (Figure 2) can be attributed to anion interaction with micelles in the mobile phase. The retention time of the selected anions can be reduced by increasing the concentration of the micellar reagent (Figure 2(a),... 

The retention of the anions on a loaded octadecyl-bonded silica column in the presence of hexadecyltrimethylammonium chloride micellar mobile phase follows the order... 

This order is similar to the anion selectivity order found on a typical strongly basic anion exchanger. Figure 2(b) illustrates a separation of five inorganic anions with a 1.36 x 10 1M hexadecyltrimethylammonium chloride micellar mobile phase. No buffer salts or organic modifier were used in order to accomplish this separation. 

The above results show that conventional HPLC can be used with UV detection for the determination of inorganic anions, namely 103, N02-, Br-, N03 and I" with a cationic micellar mobile phase. One of the attractive features of this procedure is the ability to control retention by control of the concentration of aqueous micellar hexadecyltrimethylammonium chloride rather than by the use of organic modifiers. 

Figure 2. (b) conditions as in (a) but mobile phase. 5 x 10"Vl hexadecyltrimethylammonium chloride. "Reproduced with permission from Ref. 38. Copyright 1984, Royal Society of Chemistry, London". ... 

SDS sodium dodecyl sulfate HDTC1 hexadecyltrimethylammonium chloride HDTBr hexadecyltrimethylammonium bromide Brij 35 polyoxyethylene (23) lauryl ether DTAC dodecyltrimethylammonium chloride TTAC1 tetradecyltrimethylammonium chloride HDPB hexadecylpyridinium bromide KDC potassium decanoate SPFO sodium perfluorooctanoate KTC potassium tetradecanoate... 

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