Liquid Chromatographic Determination of Cationic Surfactants in Environmental Samples using a Continuous Post-Column Ion-Pair Extraction Detector with a Sandwich Phase Separator

Determination of the Quaternary Ammonium Surfactant Ditallowdimethylammonium in Digested Sludges and Marine Sediments by Supercritical Fluid Extraction and Liquid Chromatography with Postcolumn Ion-Pair Formation

“…The extraction coil (1000 mm × 0.7 mm) was of poly(ether ether ketone) (PEEK; Flexipeek, Omnilab AG, Mettmenstetten, Switzerland) coiled to a helix of 1.5 cm diameter or stainless steel coiled to a helix of 3 cm diameter. The sandwichphase separator 36 was purchased from Prof. U. A. Th.…”

“…Aromatic surfactants like LAS can be determined by HPLC with UV absorption or fluorescence detection, − but aliphatic surfactants lacking chromophores are not directly amenable to photometric detectors. Several procedures for the determination of DTDMAC in various environmental matrices have been published, including a colorimetric method commonly referred to as disulfine blue active substances (DBAS), a combination of DBAS and thin-layer chromatography, ,, a combination of TLC or chromatography on aluminum oxide and infrared spectroscopy, , an isocratic HPLC method coupled with conductometric detection, ,,− and an isocratic or gradient , HPLC method applying postcolumn ion-pair formation and extraction with UV/vis or fluorescence detection. Gas chromatography has been used for the qualitative determination of long-chain cationic surfactants by converting them to the corresponding tertiary amines by thermal decomposition in the injector port and subsequently analyzing them in the GC. ,, The potential of FAB-MS techniques for the determination of trace levels of cationic surfactants in aqueous environmental matrices has also been demonstrated. , …”

Occurrence of cationic surfactants and related products in urban coastal environments

“…In fact, the qualitative analysis of sediments (Table I) collected in the vicinity of the Barcelona sewage outfall and its area of influence (Figure 1) showed clear evidence of dimethyldialkylammonium salts, when the methanol extracts were directly analyzed by FAB-MS. Although colorimetric and chromatographic methods exist for the determination of cationic surfactants in aquatic samples (9)(10)(11)(12)(13), the FAB-MS technique (14) provides rapid and conclusive information on the chemical identity of the species, namely, the number and length of the alkyl chains. These are indicated in the representative spectrum shown in Figure 2.…”

Analysis of Cationic Surfactants by Microbore High-Performance Liquid Chromatography−Electrospray Mass Spectrometry

“…HPLC-MS Methods. For the analysis of DSDMAB, DEQ, and DEEDMAC, gradient elution programs with various combinations of CHCl 3 , CH 3 OH, and CH 3 CN were tested; a combination of these solvents has been already used for the analysis of DTDMAC and other cationic surfactants . The final solvent combinations and the gradient programcalled method 1are shown in Figure .…”

“…Therefore, since 1982, a method utilizing HPLC with conductivity detection , has been widely used. Other detection techniques for the analysis of DTDMAC are, for example, the evaporative light scattering detector and the postcolumn ion-pair formation with phase separation and UV detection. , These techniques have in common that the distinction between different DTDMAC homologues is difficult because the complete chromatographic separation of all homologues is nearly impossible. To determine the concentration of single homologues, for example, to monitor the environmental fate of surfactants, other techniques are necessary.…”