Surfactant tests

Turbidity measurements were determined using the dipping probe colorimeter. The light frequency was 650 nm. Deionized water transmittance was set at 90. The surfactant test solutions were stirred ( — 3500 rpm) and maintained at 75°C. Active surfactant concentration was 0.1% wt. Solution volume was 100 cm1. A 26.5% CaCU (95,699 ppm CaJ+) solution was added via syringe in 0,10 ml increments to the lower portion of the surfactant solution. 

In an extensive study by Read et al. [93], 10 anionic surfactants were evaluated for their ability to remove pyritic sulfur and ash from ultrafine Illinois no. 5 coal by flotation processes. The authors observed that of the commercially available surfactants, sodium dodecyl sulfate was the most effective on either a weight or a molar basis, followed by a linear AOS (average molweight 272) and alkylpolyethoxylated sulfonates. Of the noncommercial surfactants tested, -(E -b-dodecene-b-suIfonate (f0) was the most effective and better than any commercial surfactant on a dosage/recovery basis. 

In a broad evaluation also the sulfosuccinate disodium laureth sulfosuccinate (DLSS) was a part of a variety of surfactants tested for their dermatological mildness, and some different test methods were applied [16]. Products were compared applying in vitro methods (Zein test, hemolysis) and in vivo methods (Duhring-Chamber test, skin mildness by intracutaneous test on mice and topical application on hairless mice, mucous membrane irritation according to the Draize procedure on rabbit eyes). In the Duhring-Chamber test the DLSS elicited no reactions in the animal tests it ranged in the least irritant third of the 15 products tested. 

SURFACTANT TEST TEMPERATURE /or d S H FA PM S AT EACN=0 /g dm-3 S VALUE FOR OILS/g cbf3 (MEASURED OR EXTRAPOLATED) OIL EACN FROM S ... 

Howard [27] determined dissolved aluminium in seawater by the micelle-enhanced fluorescence of its lumogallion complex. Several surfactants (to enhance fluorescence and minimise interferences), used for the determination of aluminium at very low concentrations (below 0.5 pg/1) in seawaters, were compared. The surfactants tested in preliminary studies were anionic (sodium lauryl sulfate), non-ionic (Triton X-100, Nonidet P42, NOPCO, and Tergital XD), and cationic (cetyltrimethylammonium bromide). Based on the degree of fluorescence enhancement and ease of use, Triton X-100 was selected for further study. Sample solutions (25 ml) in polyethylene bottles were mixed with acetate buffer (pH 4.7, 2 ml) lumogallion solution (0.02%, 0.3 ml) and 1,10-phenanthroline (1.0 ml to mask interferences from iron). Samples were heated to 80 °C for 1.5 h, cooled, and shaken with neat surfactant (0.15 ml) before fluorescence measurements were made. This procedure had a detection limit at the 0.02 pg/1 level. The method was independent of salinity and could therefore be used for both freshwater and seawater samples. 

Finally, MAbs and an immunoassay kit for LAS have been commercialized (see Table 3). The working range of the assay is between 20 and 500 pg L1. The antibodies are highly specific for LAS with alkyl chains between C8 and C12, whereas other anionic and nonionic surfactants tested showed no cross-reactivity. 

Arechabala, B., Coiffard, C., Rivalland, P., Coiffard, L. J. M. and de Roeck-Holtzhauer, Y. (1999). Comparison of cytotoxicity of various surfactants tested on normal human fibroblast cultures using the neutral red test, MTT assay and LDH, J. Appl. Toxicol., 19, 163-165. 

Fig. 8 Soil rennoval from wool by different anionic surfactants. Test conditions tarperature, 30 °C time, 15 min concentration, surfactant 015 g/L + Na2S0 1.5 g/L soil, sebuiVpigment mixture surfactant (1) C 2 2 4 alcohol 2B0 sulfate, (2) C 5 ] g olefinic sulfonate, (3) "16-18 fatty ester,...

The reason for these differences is not well known but it is interesting to speculate. The lower HLB surfactants tested are also those with the shortest hydrophilic chains, and so the smallest molecular areas (10). They should therefore have the highest concentrations at the LDL2 surface at saturation causing disruption and solubilization. The slow action of 012 23 could be due to slow replacement of 0 2 23 molecules by lower HLB impurities in the surfactant samples. 

Zhong et al. (2003) studied the apparent solubility of trichloroethylene in aqueous solutions, where the experimental variables were surfactant type and cosolvent concentration. The surfactants used in the experiment were sodium dihexyl sulfo-succinte (MA-80), sodium dodecyl sulfate (SDS), polyoxyethylene 20 (POE 20), sorbitan monooleate (Tween 80), and a mixture of Surfonic- PE2597 and Witconol-NPIOO. Isopropanol was used as the alcohol cosolvent. Eigure 8.20 shows the results of a batch experiment studying the effects of type and concentration of surfactant on solubilization of trichloroethylene in aqueous solutions. A correlation between surfactant chain length and solubilization rate may explain this behavior. However, the solubilization rate constants decrease with surfactant concentration. Addition of the cosolvent isopropanol to MA-80 increased the solubility of isopropanol at each surfactant concentration but did not demonstrate any particular trend in solubilization rate of isopropanol for the other surfactants tested. In the case of anionic surfactants (MA-80 and SDS), the solubility and solubilization rate increase with increasing electrolyte concentration for all surfactant concentrations. 

Figure 27. Calcium ion sequestering ability of Cn-n secondary alcohol ethoxyl-ates in combination with an anionic surfactant. Test conditions surfactant concentration nonionics—0.1 wt % anionics—0.1 wt % B = without nonionics (blank). ((-%-) with sodium laurate ( A ) with SDS (-A-) with SAS ( M ) with LAS (- A ) with AOS)...

Of the surfactants tested, AEGS surfactants produced the most persistent foams at high salinity and elevated temperatures in the presence of synthetic and crude oils (in one atmosphere experiments). ... 

At the time of the surfactant test, the WAG process had increased oil production, but there were two main problems ... 

Keniston RC, Noland GL, Pernoll ML. The effect of blood, meconium, and temperature on the rapid surfactant test. Obstet Gynecol 1976 48 442-6. 

The Ocular Irritection assay has been used for over 20 years to assess the ocular irritancy of industrial chemicals, pharmaceuticals, textile, petrochemicals, surfactants and cosmetic products. It represents a refinement of the former Eytex method that takes into account the recommendations made during earlier multilaboratory trials [1], The system underwent substantial revisions including the development of a single protocol, clear procedures for surfactants testing, and a well-defined applicability domain. It is presented as a kit comprising instrumentation and computer software that have been integrated to provide an automated in vitro test. Furthermore, because of its biochemical nature, Ocular Irritection has a long shelf-life (years) and can be readily available across the world. 

Each of the alkyl triamine ligands has sufficient solubility ( Xl>0.01 ) in the surfactants tested to provide adequate metal chelating capacity. However, the relatively small values of found for DDPA, limit its effectiveness. With DDIEN and HDPA,... 

The ionic type of a dye sample can be determined by using ionic surfactants. The anionic dyes can be precipitated by cationic surfactants and vice versa. If a colorant sample would not be affected by either cationic or anionic type of surfactants, it could be a disperse dye with non-ionic dispersants. The surfactant test should be carried out at room temperature and a surfactant solution is added into the dye solution dropwise with the help of a magnetic stirrer. The mixture should then be allowed to stand for 30-60 min for precipitation to develop. Precipitation is the positive indication of the opposite type of ion for dyes in relation to the ionic... 

Surfactants tested in this manner are listed in Table II along with pertinent physical data. The efficiency of a given surfactant, in terms of exposure time required to obtain photo-diminished adhesion in the above example, depends on two factors the pK of the surfactant and the log (critical micelle concentration), log (CMC). 

A large and positive A indicates a strong interaction and would imply an efficient photodissipation of adhesion for the surface-surfactant pair. Figure 2 shows that this expectation is born out for nickel (IEPS = 10), aluminum (9), tin (4), and silicate (2) with the surfactants tested. 

List 1. Chemical Classes of Surfactants Tested for Solubility... 

None of surfactants tested contributed to the quantification of SRB in the sample with the higher oil content (sample A). However, for the GAnB group, surfactants Tween 60 and Tween 80 caused favorable effects in the quantification. 

Only Tween 60 did not show a positive effect for SRB quantification in sample C (water contaminated with oil). On the other hand, GAnB quantification was increased with the addition of all surfactants tested, except with the addition of SDS, leading to the highest concentration of cells (2.5 x 10 cells/ml). 

Water has a typical surface tension of 72mN/m and, as can be seen fi om the above table, all the surfactants tested reduced the surface tension of the s em, and as a result the aqueous medium wets more efficiently. For the silicone surfactants the best results were achieved with product A, a low molecular weight material. Trisiloxane A gives a very low figure that is only improved upon by the fluorosurfactant. The Critical Micelle Concentration (CMC) is the required level of product to initiate the formation of micelles in the bulk of the liquid. Up to this point the surfactant added to die water migrates to the liquid/air interface to form a film which reduces the surface tension. The low CMC for A shows its high packing efficiency at the intoface, in the much lower level required in comparison to the other products. 

Selected four kinds of surfactants on single surfactant measurement, it can be seen that the contact Angle is smaller in the relatively high concentrations of surfactant In the low concentration of the contact Angle is bigger. Thus, it is necessary to do the two surfactant test. Comparison by the surface tension and contact angle, the optimal formula are Pj, Pj. Pji The surface tension is 22.70 dy/cm, when the ratio of amide of fatty alcohols and alkyl quaternary ammonium salt is 2 1 Pji The surface tension is 23.51 dy/cm, when the ratio of JFC and Triton X-100 are 1 1. For Pj, Pj, according to the choice of different coal condition such as the critical surface tension of the specific analysis. 

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