Detergency, measurement

A number of wash tests were carried out which proved that certain LSDAs had the ability to potentiate the detergency of soap [24]. Detergency measurements were carried out using standard soiled cloths in 300 ppm water in the Tergo-... 

Liquid soap or detergent, measuring spoons, pump-spray bottles, plants infested with household or garden insect pests such as houseflies or aphids... 

Flush the system thoroughly with water to remove all traces of detergent measure the pure water flux through the membrane modules under standard test conditions. Even after cleaning, some degree of permanent flux loss over time is expected. If the restoration of flux is less than expected, repeat steps 1-3. 

This assay, which does not require the addition of lipids or detergent, measures the ability of CT or LT to ADP-ribosylate itself in the absence of another ADP-ribose acceptor (except water). ARF added to this assay will also be ADP-ribosylated, but the ADP-ribosylation of it or CT under these conditions does not appear to decrease CT activity or the ability of ARF to stimulate CT (Tsai ef a/., 1991). Reaction products are separated by SDS-PAGE and analyzed by autoradiography as described for Assay 1 (Section 2.3). This assay is the most sensitive of all those listed here and can be used to verify toxin activity observed in other assays. 

We have used several, complementary approaches to measure TAL biodegradability based on the OECD screening test. These include the use of radioactively labelled detergent measurements of the growth rates and maximum counts of microorganisms from natural sources on each component of TAL in a basal salts medium and finally, glc analysis of each component in solutions incubated with soil suspensions. The evidence accumulated to date suggests that the components of TAL are readily metabolised by microorganisms. 

Figure 12.15 Phase behavior of nonionic surfactants and detergency three-phase temperatures versus n (right) and detergency (measured as reflectancy R) versus temperature (left)...

Lubricants. Petroleum lubricants continue to be the mainstay for automotive, industrial, and process lubricants. Synthetic oils are used extensively in industry and for jet engines they, of course, are made from hydrocarbons. Since the viscosity index (a measure of the viscosity behavior of a lubricant with change in temperature) of lube oil fractions from different cmdes may vary from +140 to as low as —300, additional refining steps are needed. To improve the viscosity index (VI), lube oil fractions are subjected to solvent extraction, solvent dewaxing, solvent deasphalting, and hydrogenation. Furthermore, automotive lube oils typically contain about 12—14% additives. These additives maybe oxidation inhibitors to prevent formation of gum and varnish, corrosion inhibitors, or detergent dispersants, and viscosity index improvers. The United States consumption of lubricants is shown in Table 7. 

Quahty control testing of siUcones utilizes a combination of physical and chemical measurements to ensure satisfactory product performance and processibihty. Eor example, in addition to the usual physical properties of cured elastomers, the plasticity of heat-cured mbber and the extmsion rate of TVR elastomers under standard conditions are important to the customer. Where the siUcone appHcation involves surface activity, a use test is frequently the only rehable indicator of performance. Eor example, the performance of an antifoaming agent can be tested by measuring the foam reduction when the sihcone emulsion is added to an agitated standard detergent solution. The product data sheets and technical bulletins from commercial siUcone producers can be consulted for more information. 

Furthermore, in a series of polyoxyethylene nonylphenol nonionic surfactants, the value of varied linearly with the HLB number of the surfactant. The value of K2 varied linearly with the log of the interfacial tension measured at the surfactant concentration that gives 90% soil removal. Carrying the correlations still further, it was found that from the detergency equation of a single surfactant with three different polar sods, was a function of the sod s dipole moment and a function of the sod s surface tension (81). 

Redeposition of sod can be estimated simultaneously with net sod removal (detergency) by including a white swatch with the soded swatches. It also can be estimated separately by adding a measured amount of sod to a fresh wash bath, then treating the white swatch ia this standard-sod bath. The former method is, superficially at least, more reaUstic. The latter method, however, is frequently of greater value ia development work because both the quantity and composition of the sod are known and can be controlled. 

A number of excellent studies have used a variety of radiolabeled sods to iavestigate the removal of small amounts of colorless sods such as ods (102—104). By proper use of different radiolabels (such as and " C), the preferential removal of various components ia a sod mixture can be followed. In these cases ia particular, detergency can also be calculated from measurements of the amount of radioactivity that is removed from the fabric and is found ia the wash Hquor. 

Detergent Methods. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) methods (2), later modified for human foods (13), measure total insoluble plant cell wall material (NDF) and the cellulose—lignin complex (ADF). The easily solubilized pectins and some associated polysaccharides, galactomaimans of legume seeds, various plant gums, and seaweed polysaccharides are extracted away from the NDF. They caimot be recovered easily from the extract, and therefore the soluble fiber fraction is lost. 

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