TTAB

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-... 

Other cationic surfactants such as TTAB, DTAB, DODAB, STAC, CEDAB, and DDDAB have been used in CL reactions with less frequency. Thus, tetradecyltrimethylammonium bromide [TTAB] has been used to increase the sensitivity of the method to determine Fe(II) and total Fe based on the catalytic action of Fe(II) in the oxidation of luminol with hydrogen peroxide in an alkaline medium [47], While other surfactants such as HTAB, hexadecylpiridinium bromide (HPB), Brij-35, and SDS do not enhance the CL intensity, TTAB shows a maximum enhancement at a concentration of 2.7 X 10 2 M (Fig. 11). At the same time it was found that the catalytic effect of Fe(II) is extremely efficient in the presence of citric acid. With regard to the mechanism of the reaction, it is thought that Fe(II) forms an anionic complex with citric acid, being later concentrated on the surface of the TTAB cationic micelle. The complex reacts with the hydrogen peroxide to form hydroxy radical or superoxide ion on the... 

TEP TL TLC TMB TMP TMP TMPG TNS TPB TRIS TRITC TTAB UA USDA-FSIS Triethylphosphine Total luminescence Thin layer chromatography T etramethylbenzidine 2,4,6,8-Tetrathiomorpholinopyrimido [5,4-d] pyrimidine Trimethylphosphine S S -Trimethoxyphenylglyoxal Potassium 2-p-toluidinylnaphthalene-6-sulfonate Tetradecylpyridine bromide Tris (hydroxymethyl) aminomethane Tetramethylrhodamine isothiocyanate Tetradecyltrimethyl ammonium bromide Uric acid U.S. Department of Agriculture-Food Safety and Inspection Service... 

PARTITION COEFFICIENTS (P ), RETENTION FACTOR (K) AND MOBILITY DATA OF DYE INTERMEDIATES MEASURED WITH A PHOSPHATE-(TTAB) BUFFER AT PH 5.0 ... 

Chromate, TTAB, borate CZE system with indirect detection Inorganic anions 52... 

A wide choice of cationic surfactants such as CTAB (cetyltrimethylammonium bromide), CTAH (cetyltrimethylammonium hydroxide), TTAB (tetradecyltrimethylammonium bromide), TTAOH (tetradecyltrimethylammonium hydroxide), MTAB (myristyltrimethylammo-nium bromide), OFM (OFM Anion-BT, Waters, Milford, MA, USA), HDB (hexadimethrine bromide), and many others may be used to reverse the EOF. CTAH and TTAOH should be preferred to CTAB and TTAB to avoid interference from bromate contamination. The capillary coating is performed just by rinsing with the BGE containing this flow modifier or even with an additional rinse step with a solution containing this flow modifier. 

TTAB) as surfactant and diethylether, n-heptane, cyclohexane, chloroform, or octanol as oil phase. Table 5 summarizes the values of N for the test mixtures in microemulsions containing different organic solvents with cationic surfactants. 

Table 5 Number of Theoretical Plates (N) for the Test Mixture Component in Microemulsions Containing Different Organic Solvents with TTAB...

Cetyltrimethyl ammonium bromide (CTAB) dodecyltrimethyl ammonium bromide (DTAB) tetradecyltrimethyl ammonium bromide (TTAB) trioctyl-methyl ammonium chloride (TOMAC) N-benzyl-N-dodecyl-hf-bis(2-hy-droxy ethyl) ammonium chloride (BDBAC) cetyl pyridinimn chloride (CPC) quaternary ammonium salt with carbon atoms of R ranging from 8-10 (CHj Rj N+ CL) (Aliquat 336)... 

Tetradecyl trimethyl ammonium bromide (TTAB)/heptane/octanol Thermal stability [62]... 

Cabral and coworkers [253] have investigated the batch mode synthesis of a dipeptide acetyl phenylalanine leucinamide (AcPhe-Leu-NH2) catalyzed by a-chymotrypsin in a ceramic ultrafiltration membrane reactor using a TTAB/oc-tanol/heptane reverse micellar system. Separation of the dipeptide was achieved by selective precipitation. Later on the same group successfully synthesized the same dipeptide in the same reactor system in a continuous mode [254] with high yields (70-80%) and recovery (75-90%). The volumetric production was as high as 4.3 mmol peptide/l/day with a purity of 92%. The reactor was operated for seven days continuously without any loss of enzyme activity. Hakoda et al. [255] proposed an electro-ultrafiltration bioreactor for separation of RMs containing enzyme from the product stream. A ceramic membrane module was used to separate AOT-RMs containing lipase from isooctane. Application of an electric field enhanced the ultrafiltration efficiency (flux) and it further improved when the anode and cathode were placed in the permeate and the reten-tate side respectively. 

A-Benzoyl-A-phenylhydroxylamine, variamine blue, vanadox, PAN,b PAR,b TTAb... 

Fig. 5. An analysis of a coarse atmospheric aerosol extract by CE and IC [49]. CE conditions a 57 cmX75 xm I.D. capillary, distance to detector, 50 cm. Electrolyte 2.25 mM PMA (pyromel-litic acid), 0.75 mM HMOH (hexamethonium hydroxide), 6.50 mM NaOH and 1.60 mM TEA (triethanolamine), pH 7.7 or 2.0 mM NDC (2,6-naphthalenedicarboxylic acid), 0.5 mM TTAB (tetradecyltrimethylammonium bromide) and 5.0 mM NaOH, pH 10.9 30 kV (PMA) or 20 kV (NDC) pressure injection for 10 s indirect UV detection at 254 nm (PMA) or 280 nm (NDC). IC conditions an IonPac-ASlO column with an IonPac-AGlO guard precolumn conductivity detection using an anion self-regenerating suppressor (ASRS-I) in the recycle mode. Analytes 2, chloride 3, sulfate 5, nitrate 6, oxalate 7, formate 10, hydrocarbonate or carbonate 11, acetate 12, propionate 14, benzoate.

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