Judul: Intercalation Xilanol Orange on the Natural Zeolit and Their Application as the Zeolite Modified Electrode for Cd Measurement
Abstrak: Zeolite is a mineral inorganic micropores of alumina silicate hydrate compounds with alkali metals and alkaline that has a skeleton-shaped cavity. Zeolite mineral have a distinctive trait that matters, namely is high cation exchange capacity so the zeolite is not only used as nutrient sinks, but can be used to bind heavy metals ions. Zeolite is divided into natural zeolites and zeolite synthesis, generally adsorption capacity of natural zeolite is lower than the zeolite synthesis, so to enhance the capacity of the adsorption, the character of natural zeolite surfaces need to be modified with surface modification process through a variety of methods, one of the method is intercalation. Intercalation is the insertion of the guest species (ion, atom, or molecules ) between layer compound. The purpose of this research is intercalated color substances is xilenol orange into natural zeolite Lampung and applying it as a selective electrode for the determination of the concntration of ions Cd. Through the process of intercalation is expected to improve the usefulness and added value of the zeolite. Modified zeolite is expected to have a specific surface properties of cadmium ions so that the adsorption can be used as a tools in the set up of selective ion electrode. Electrode is made by mixing powder carbon, zeolite intercalated, mineral oil on a comparison of 6: 1: 3 so that a homogeneous paste is obtained. Paste is then packed in glass tubes with a diameter of 3 mm in copper wire as the tools which has give electrical contact. Zeolite intercalated xilenol orange prepared by mixing the two grams of zeolite (who had previously been activated) with 100 mL of orange xilenol in the range pH 5–10. Activation of the zeolite is carried out by means of washing away 60 mesh size zeolite with 1 M HCl and heating on temperatures 130o C. Results show, that xilenol orange can be intercalated into a zeolite, this is seen from the spectrum FTIR which had absorption at num waves 1383 cm-1. That exhibits absorption of' S=O symmetric and asymmetrical in a –SO3H group is suspected because XO having a SO3 group so as to cause the presence of an attack HSO3 of XO on protons of a zeolite. Binding of xilenol orange also can be detected of a decrease in cristalinty on difractogram X rays. The measurement of the concentration of ions Cd2+ best occurring at pH 9. It can be seen with a peak of pH on that point, reach a maximum with the percentage of 46 %. The measurement of working electrodes using a paste of carbon which is modified of the zeolite intercalated xilenol orange indicated the result that better than the measurements of an electrode paste carbon without modification of the zeolite. Repeatabilty measurement by ZMCPE which made against ion Cd 10-6 M is good enough. That shown by the results obtained from the current average of 91.82 A with standard deviation of 0,342. XRD results show that the zeolite used in this research is a clinoptilolite type. Because it has a main peak at 22.5
Keyword: Lampung natural zeolite, xylanol orange, intercalation, zeolite modified electrode, cadmium, potensiostat