Detergents analysis

B. M. Milwidsky and D. M. Gabriel, Detergent Analysis AHandbook for Cost-Effective Quality Control, MiceUe Press, Cranford, N.J., 1989. 

In the 1970s a new analysis method was developed, referred to as isota-chophoresis [247]. Capillary isotachophoresis with conductivity detector is very useful in detergent analysis for the determination of all kinds of ionic species [248]. It is also useful for the determination of MCA in ether carboxylates. 

Milwidsky BM and Gabriel DM (1982) Detergents Analysis. A Handbook for Cost-Effective Quality Control. New York Wiley. 

Milwidsky Gabriel Detergent analysis (editor G. Godwin)... 

Voogt, R, Ion-exchangers in detergent analysis. Part II, Rec. Trav. Chim., 1959, 78, 899-912. Bey, K., TLC analysis of surfactants (in German), Fette, Seifen, Anstrichm., 1965,67,217-221. Daradics, L., J. Palinkas, Synthesis and analysis of fatty acid sarcosides, Tenside, Swfactants, Deters., 1994,3/, 308-313. 

Voogt, R, Ion-exchangers in detergent analysis, Rec. Trav. Chim., 1958,77,889-901. 

Fuller, M. R, G. L. Ritter, C. S. Draper, Partial least-squares quantitative analysis of IR spectroscopic data. Part II Application to detergent analysis, App. Spectro.se., 1988,42, 228-236. 

The type of behavior shown by the ethanol-water system reaches an extreme in the case of higher-molecular-weight solutes of the polar-nonpolar type, such as, soaps and detergents [91]. As illustrated in Fig. Ul-9e, the decrease in surface tension now takes place at very low concentrations sometimes showing a point of abrupt change in slope in a y/C plot [92]. The surface tension becomes essentially constant beyond a certain concentration identified with micelle formation (see Section XIII-5). The lines in Fig. III-9e are fits to Eq. III-57. The authors combined this analysis with the Gibbs equation (Section III-SB) to obtain the surface excess of surfactant and an alcohol cosurfactant. 

W. E. Bishop, C. C. Kuta, aud C. A. Pittiager, "Life Cycle Analysis aud Its Relevaace to the Detergent Industry," paper presented Nen> Honan s 92 CSMA.IAOCS Detergent Industry Conference, Bolton Lauding, New York, Sept. 14, 1992. 

As with the case of energy input, detergency generally reaches a plateau after a certain wash time as would be expected from a kinetic analysis. In a practical system, each of its numerous components has a different rate constant, hence its rate behavior generally does not exhibit any simple pattern. Many attempts have been made to fit soil removal (50) rates in practical systems to the usual rate equations of physical chemistry. The rate of soil removal in the Launder-Ometer could be reasonably well described by the equation of a first-order chemical reaction, ie, the rate was proportional to the amount of removable soil remaining on the fabric (51,52). In a study of soil removal rates from artificially soiled fabrics in the Terg-O-Tometer, the percent soil removal increased linearly with the log of cumulative wash time. 

The Hterature on analytical methods is voluminous and not easily summari2ed (123—130). Often the greatest expertise ia the analysis of complex detergent mixtures resides with ia-house personnel ia iadividual companies who may regard their methods as proprietary iaformatioa. 

The detergent method for insoluble fiber superseded the cmde fiber method and became the method of choice for insoluble fiber analysis until the 1980s, when methods were developed to recover soluble fiber as well. Some analysts still prefer the NDF procedure for insoluble fiber. The method is simple, inexpensive, reproducible, and amenable to routine assays. The disadvantage is the inabiUty to recover the soluble fraction. See Reference 14 for more information on detergent methods. 

The system of anionic surfactants is another example of organic compounds mixtures. The procedure of their determination is proposed using coordinate pH in two-dimensional spectra of ionic associates anionic surfactants with rhodamine 6G. This procedure was tested on the analysis of surfactant waters and domestic detergents. 

Longman, G. F. The Analysis of Detergents and Detergent Products. J. Wiley Sons, Ltd., Chichester 1975. 

Also the a-ester sulfonates are less important today. In the Federal Republic of Germany, for example, the total production of surfactants was about 700,000 t/a in 1993. For a more detailed analysis of different types of surfactants, use must be made of data collected before the unification of Germany. In 1988 the consumption of surfactants in detergents was about 227,500 t/a, the consumption of anionic surfactants was about 116,000 t/a and less than 1000 t/a of a-sulfo fatty acid esters [5] (the values refer to German Detergent Law). 

In another study of the physical behavior of soap-LSDA blends, Weil and Linfield [35] showed that the mechanism of action of such mixtures is based on a close association between the two components. In deionized water this association is mixed micellar. Surface tension curves confirm the presence of mixed micelles in deionized water and show a combination of optimum surface active properties, such as low CMC, high surface concentration, and low surface concentration above the CMC. Solubilization of high Krafft point soap by an LSDA and of a difficulty soluble LSDA by soap are related results of this association. Analysis of dispersions of soap-LSDA mixtures in hard water shows that the dispersed particles are mixtures of soap and LSDA in the same proportion as they were originally added. These findings are inconsistent with the view that soap reacts separately with hard water ions and that the resulting lime soap is suspended by surface adsorption of LSDA. The suspended particles are responsible for surface-active properties and detergency and do not permit deposits on washed fabric unlike those found after washing with soap alone. 

Proteases are hydrolytic enzymes with important application in industries, in particular, in detergent and in the food industry. A metagenomic study in which 100 000 plasmid clones were screened for proteolytic activity found one positive done, which was determined to be novel by sequencing analysis [84]. 

We described here the characterisation of the pemB gene and its product the second PME of E. chrysanthemi. The biochemical analysis of the purified protein indicated that PemB is actually an enzyme that demethylates pectin, leading to formation of methanol and PGA. However, PemB is more active on methylated oligogalacturonides than on polymeric pectin. The activating effect of non-ionic detergents on PemB was never pointed out for other pectinases and it is a characteristic of many membrane enzymes (21). 

Further advance toward a high-resolution structure of Ca -ATPase requires three-dimensional crystals of sufficient size and quality for X-ray diffraction analysis [179]. A prerequisite for the formation of three-dimensional crystals is the solubilization of the enzyme from its membrane environment by detergents [180,181]. Since the detergent-solubilized Ca -ATPase is notoriously unstable, the first task was to find conditions that preserve the ATPase activity of solubilized enzyme for several months. 

---