Bismuth active substances

DIN German Standard Method for the Examination of Water, Waste Water and Sludge General Measures of Elfects and Substances (Group H). (A) Determination of Methylene Blue Active Substances (H23-1), (B) Determination of Bismuth Active Substances (H23-2), (C) Determination of the Disulfine Blue Active Substances (H20). VCH, Weinheim, Germany, 1992. 

ABS AE AE/P AES AG AOS APEO APG AS BiAS BM c6(EO)3 CNPEC CTAS D DATS DCPEG DEEDMAC branched alkylbenzene sulfonate alcohol ethoxylate alcohol ethoxylate/propoxylate alkylether sulfate alkyl glucamide a-olefin sulfonate alkylphenol ethoxylate alkyl polyglucoside alkyl sulfate bismuth active substances alkyldimethylbenzyl ammonium triethylene glycol monohexyl ether carboxylated nonylphenoxy carboxylates cobalt thiocyanate active substances R2S10(o.5)2 dialkyl tetralinsulfonate dicarboxylated PEG ditallow ester of di(hydroxyethyl)dimethyl ammonium chloride... 

The bismuth active substances (BiAS) method for the determination of nonionic surfactants with barium tetraiodobismuthate (BaBil4, modified Dragendorff reagent) is used in the standardized (DIN-Norm) procedure in Germany, as well as in other countries. Ba as a hard Lewis acid forms cationic coordination complexes with the polyethoxylate chain of the nonionic surfactants, which are precipitated by [Bim in the presence of acetic acid. The orange precipitate is then dissolved with ammonium tartrate solution, and the released bismuth ions are determined by potentiometric titration with pyrrolidinedithiocarbamate solution. Waters et al. optimized the BiAS procedure by introduction of a cation/anion exchange clean-up of the sublation extracts. The BiAS procedure fails to determine ethoxylates with less than five ethoxy units because these compounds are not precipitated by barium tetraiodobismuthate. Thus, this procedure is not suitable for determination of APEO metabolites, i.e., the shorter APEO and AP. ... 

The same relates to the analytical methods, where for anionic, nonionic and cationic surfactants, various colorimetric procedures (MBAS, bismuth active substance(s) (BiAS), and disulfine blue active substance(s) (DSBAS)) were introduced. Since these methods analyse only the loss of surface-activity or primary degradation, other analytical approaches have been employed in the last 10 years in order to characterize the total or ultimate degradation. These include methods such as high performance liquid chromatography (HPLC), gas chromatography (GC) GC/mass spectrometry (MS), and the measurement of total organic carbon (TOC) and chemical oxygen demand (COD). 

Waters, J., J. T. Garrigan, A. M. Paulson, Scope and limitations of the bismuth active substances procedure (Wickbold) for the determination of nonionic surfactants in environmental samples. Water Res., 1986,20,247-253. 

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