Detergent electrode

Direct determination of surfactants in complex matrices can also be carried out using ion-selective electrodes. Depending on the membranes and additives used, the detergent electrodes are optimized for the detection of anionic surfactants [81], cationic surfactants [82], and even nonionic surfactants [83]. The devices are sensitive to the respective group of surfactants but normally do not exhibit sufficient stability and reproducibility for their use in household appliances. With further optimization of membrane materials, plasticizers and measurement technology, surfactant-selective electrodes offer high potential for future applications. 

Knittel, D., W. Schollmeyer, Influence of additives on the response of detergent electrodes in titrations of anionic surfactants, SOFW J., 1998,124,338,340-342. 

Conductivity sensors are most commonly used for safety purposes in household appliances. Presence and absence of washing liquor, detergency, and water softener can be easily measured and proper operation ensured [71]. The various applications mainly differ by their design of electrode geometry and methods for electrical measurement. Due to the close relation between ionic conductivity and water hardness, the automatic water softener in an automatic dishwasher can be controlled by a conductivity sensor [72]. To isolate the transmission of the measured value from the process controller, the conductivity sensor could incorporate an opto-electronical coupling [73]. Thus, protective insulation of the electrodes in a washer-dryer could be ensured. 

The water-splitting activity of detergent-solubilized and AP-trapped PS2 reaction centers was measured using a Clark electrode. As shown in Figure 4, differences between the two types of samples were minimal, with a slight decrease of activity when the pH of the P-DM solution was shifted to pH 8 and a moderate increase following addition of A8-35, dilution below the CMC of p-DM and treatment with BioBeads. 

The SDS-containing solution is supplemented with an excess of a nonionic detergent, e.g., Triton X-100. The electrode buffer is a buffer with low ionic strength, without SDS, and pH nearby the pi of the protein of interest. During electroelution SDS migrates to the anode. 

Ruzicka, et al. (11) increased the oil solubility gf phosphate ester anions to increase the sensitivity of the Ca electrode. Gavach, et al. (12) and Birch, et al. (13) made detergent sensors for cations and anions. 

Detection Permeant ions (fluorescent probes or ion electrode) carotenoid shift anilinonaphthalen-sulfonate pH meter (inside after detergent) P-NMR flow dialysis aminoacridine... 

Use (Solid) Manufacture of glass and refractory material, welding rods, high-temperature mortars, binder in carbon arc-light electrodes, detergents, catalyst, adhesives. 

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