Electrospray mass spectrometry (ESMS) has been used to identify the mixture of components in three nonionic surfactants, nonylphenol ethoxylate (NPE), secondary alcohol ethoxylate (SAE), and primary alcohol ethoxylate (PAE). In each case singly protonated species are observed with the number of ethylene oxide units ranging from 4 to 16. Collisionally activated decomposition of protonated SAE leads to cleavage of the secondary carbon-oxygen bond to give protonated ethylene oxide fragment ions. ESMS is used to show that the products of the photocatalytic decomposition of SAE are the same as those produced by the collisionally activated decompositions. The surfactants can also be singly ionised in solution
Abstract-The Microtox" test was successfully used to measure EC50 values of nonionic polyethoxylate surfactants. However, toxicity measurements of real samples that contain surfactants above a particular concentration, termed the critical toxicity concentration (CTC) are not valid. These samples require dilution before the test is performed, and because the relationship between toxicity and concentration is not linear above the CTC, the EC50 cannot be extrapolated back to give the toxicity of the original concentrated sample and a true estimation of toxicity is therefore not possible. This phenomenon may be related to the minimum surface tension requirement of the bacteria or other physical properties of the surfactant such as the tendency to assemble at interfaces and surfaces and the tendency to form micelles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.