Pembuatan Sensor Lutetium (III) Berbasis Senyawa Dodecandioylbis (1-Phenyl-3-Methyl-5-Pyrazolone) untuk Penentuan Ion Lutetium (III) Secara Potensiometr (Preparation Lutetium (III) Sensor with 4-Dodecandioylbis(l-Phenyl-3-Methyl-5-i Pyrazolone) for Determination of Lutetium (III) Potentiometric )