Untreated or grafted fibers were packed in a stainless column with a size of 150 mm length and 4 mm inner diameter. The column packed with grafted fibers was connected to the LC pump, Shimadzu LC−10 AS and rinsed
with an aqueous HCl solution,Consequently, an aqueous solution of LAS was passed through the column with a flow rate of 0.2 − 0.4 ml/min at 20℃. The solution passed through the column was collected in a glass tube at a given time by a fraction collector, Advantec SE−2120.The concentration of LAS in the collected solution was estimated from the absorbance at 223 nm in the UV spectroscopy using a Shimadzu UV−2200 spectrophotometer or a JASCO V−530UV/VIS spectrophotometer.
Experiments on adsorption of ammonium ion to fibers were carried out by two methods. The first method was similar to that for LAS as described above. An aqueous ammonium ion solution was prepared from ammonium chloride and water. The solution was passed through the column packed with fibers. The concentration of ammonium ion in the original ammonium ion solution and the eluent was measured by an ammonia meter, Ti−900KA of Tokyo Kagaku Kenkyusho Co. Ltd.
The second one is a batch system method as follows. Untreated or grafted rayon fabrics were immersed in an aqueous ammonium ion solution and the time change of the concentration of ammonium ion of the solution was measured by the ammonia meter.