Analisis Timbal pada Simplisia Daun Torbangun dengan Metode Destruksi Basah Teroptimasi secara Spektrofotometri Serapan Atom

Abstract

Penentuan kadar timbal (Pb) dalam simplisia memerlukan preparasi sampel yang tepat untuk menguraikan matriks organik. Penelitian ini mengoptimasi metode destruksi basah pada penentuan Pb dalam simplisia daun torbangun (Coleus amboinicus L.) secara Spektrofotometri Serapan Atom. Optimasi dilakukan melalui variasi jenis dan volume pereaksi serta waktu pemanasan. Efektivitas metode dinilai berdasarkan recovery, kemudian diverifikasi melalui parameter akurasi, presisi, batas deteksi, dan batas kuantitasi. Kondisi destruksi optimum diperoleh menggunakan campuran HNO3:HCl dengan volume 10 mL dan waktu pemanasan 30 menit dengan recovery sebesar 98,37% ± 3,06%. Uji ANOVA menunjukkan jenis pereaksi (p = 0,014) dan volume pereaksi (p = 0,040) berpengaruh signifikan terhadap recovery Pb, sedangkan waktu pemanasan (p = 0,817) tidak berpengaruh signifikan. Metode ini memiliki batas deteksi sebesar 0,646 mg/L dan batas kuantitasi sebesar 1,95 mg/L. Kadar Pb tertinggi sebesar 7,20 mg/L yang berada di bawah batas maksimum cemaran Pb dalam simplisia berdasarkan regulasi BPOM.

Determination of lead (Pb) levels in medicinal plants requires proper sample preparation to decompose the organic matrix. This study optimized the wet digestion method for determining Pb in torbangun leaf medicinal plants (Coleus amboinicus L.) using Atomic Absorption Spectrophotometry. Optimization was carried out by varying the type and volume of reagents and heating time. The effectiveness of the method was assessed based on recovery, then verified through parameters of accuracy, precision, limit of detection, and limit of quantitation. The optimum digestion conditions were obtained using a mixture of HNO3:HCl with a volume of 10 mL and a heating time of 30 minutes with a recovery of 98,37% ± 3,06%. ANOVA test showed that the type of reagent (p = 0,014) and volume of reagent (p = 0,040) significantly affected Pb recovery, while heating time (p = 0,817) did not significantly affect Pb recovery. This method has a detection limit of 0,646 mg/L and a limit of quantitation of 1,95 mg/L. The highest Pb level was 7,20 mg/L, which is below the maximum limit for Pb contamination in simplex based on BPOM regulations.