Determination Of Some Restricted Substances In Surfactant And Its Products

This thesis studied the determination of alkyl phenol polyoxyethylene ether, ethanolamine and formaldehyde by analysis apparatus methods.A method of HPLC-diode array detector was set up which can be used in determination of octylphenol, nonylphenol, polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether. The results show that at the selected condition, the detergent of these four substances with other surfactants can be well separated. With the concentration in the range of0.02-0.50g/L, the detection limits are0.48～0.67μg/L, these four compounds have good linear relationship between peak area and concentration, the relative standard deviations (RSD) range from0.08%to1.79%. The recoveries of the samples were96.7%-104.2%. This method is simple, quick, and with good reproducibility, and is suitable for detection of alkylphenol polyoxyethylene ether in the household products.A method which can be used in simultaneous determination of mono ethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) by Gas Chromatography was established. At the selected condition, MEA, DEA and TEA are well separated. With the concentration in the range of0.5～1.5g/L, the ethanolamine has a good linear relationship between peak area and concentration, the correlation coefficient were0.9994,0.9996,0.9995, and the limits of detection were1.14%,1.75%and2.21%respectively. Qualitative analysis was done by retention time, and external standard method determine the content. The relative standard deviations (RSD) of three surfactant samples, alkanolamide(1:1), alkanolamide(1:1.5), dodecyl benzene sulfonic acid triethanolamine, were1.14%,1.75%and2.21%. The recovery of three samples were95.2%～104.4%,96.2%～104.7%,97.4%～103.9%. This method is simple, quick, and with good reproducibility, and is suitable for detection of ethanol amine in surfactants and its products.A lab-made post-column derivatization device was used to determine the content of formaldehyde in surfactants and its products by HPLC. The limit detection of this method was56μg/L, the recoveries were99.4%～104.9%and the relative standard deviation (RSD) was less than2.3%. The method is quick, convenient accuracy and practical. With the method, some kinds of negative factors canbe avoided, such as existing of formaldehyde relievers, extracting agent is not pure or samples produce color interference, etc. The false positive results of formaldehyde detection can be avoided efficiently. And this technique is adopted in detection of free formaldehyde in surfactants and its products.