STUDI PERBANDINGAN ANALISIS UNSUR PLUMBUM (PB) DARI HASIL ELEKTROLISIS ANTARA METODE LASER- INDUCED BREAKDOWN SPECTROSCOPY (LIBS) DENGAN METODE KONVENSIONAL

Abstract

Penelitian ini bertujuan menganalisis unsur Pb hasil proses elektrolisis dengan metode alternatif laser-induced breakdown spectroscopy (LIBS) dan metode konvensional. Elektrolisis menggunakan tembaga (Cu) sebagai katoda dan karbon sebagai anoda. Unsur Pb yang terdeposisi pada katoda diirradiasi laser Nd-YAG (model CFR 200, 1064nm) dan emisinya (Pb I 405.7 nm) ditangkap spektrometer HR 2500++ yang kemudian ditampilkan dalam intensitas fungsi panjang gelombang. Hasil penelitian menunjukkan bahwa energi laser, arus listrik dan waktu deposisi proses elektrolisis yang optimum untuk karakterisasi unsur Pb masing - masing adalah 100 mJ, 5,28 mA dan 15 menit. Aplikasi metode ini untuk analisis kuantitatif larutan Pb dengan membuat kurva kalibrasi dari kosentrasi 300 ppm sampai kosentrasi terendah yaitu 0,5 ppm, serta diperoleh deteksi limit sebesar 0,44 ppm. Sebagai perbandingan metode deteksi dengan LIBS ini telah dilakukan analisis dengan metode konvensional dengan menentukan selisih massa katoda sebelum dan sesudah elektrolisis dan diperoleh hasil yang sebanding.ABSTRACTThe aim of this research was to compare between a method of laser-induced breakdown spectroscopy (LIBS) and the conventional one to analyse of Plumbum (Pb) element resulted from electrolysis process. Electrolysis used copper (Cu) and carbon (C) as cathode and anode respectively. Plumbum element which was deposited on cathode was irradiated by Nd-YAG laser (model CFR 200, 1064nm) and its emission intensity of neutral Pb I 405.7 nm in the plasma was captured by HR 2500++ spectrometer and displayed in a form of intensity as a function of wavelength. The experiment result showed that the optimum condition parameters of electrolysis: laser energy, electric current and electrolysis time duration were 100 mJ, 5.28 mA and 15 minutes respectively. An application of these conditions was done to make calibration curve of Pb element in liquid sample from 300 ppm to 0.5 ppm and resulted a limit of detection (LOD) of 0.44 ppm. As a comparison of this method, the weighed the mass of the cathode (Cu) before and after electrolysis had been calculated by conventional method. The data showed that these two methods are proportional.

Keywords

• electrolysis, Pb elemen
• laser energy
• LIBS method
• conventional method