Perbandingan metode Destruksi Basah dan Kering untuk penentuan besi dan seng dalam daun Kangkung secara Faas.

Abstract

Telah dilakukan uji banding metode destruksi basah dan kering untuk penentuan kadar besi dan seng dalam daun kangkung. Destruksi basah dilaksanakan dengan melarutkan sampel dalam 20 mililiter campuran HNO3— H2SO4 ( 3 : 1 ) pada suhu 100 °C selama 10 menit, kemudian didinginkan selama 10 menit dan ditambahkan 2 mililiter H202 30% tetes demi tetes. Pemanasan dilanjutkan secara perlahan pada. suhu 200 °C sampai diperoleh larutan jernih. Destruksi kering dilaksanakan dengan mengabukan sampel pada suhu 400 °C selama 3 jam Abu yang diperoleh dilarutkan dalam 20 mililiter HNO3 pekat. Proses pelarutan dipercepat dengan pemanasan pada. 200 °C hingga diperoleh larutan jernih. Analisis terhadap kandungan besi dan seng dilakukan secara spektroskopi serapan atom nyala (FAAS). Hasil penelitian menunjukkan bahwa metode destruksi basah menghasilkan kadar besi sebesar 2,102 ± 0,052 mg/100 g dengan nilai pungut ulang 105,1% dan kadar seng sebesar 0,101 ±-0,002 mg/100 g, nilai pungut ulang 67,8%. Metode destruksi kering menghasilkan kadar besi sebesar 2,162 ± 0,156 mg/100 g dengan nilai pungut ulang 106,6% dan kadar seng sebesar 0,255 ± 0,034 mg/100 g, nilai pungut 104,3%. Hasil uji statistika dengan tingkat keterpercayaan 95%, menyatakan nilai t hitung sebesar 0,606 untuk unsur besi dan 7,700 untuk unsur seng, sedangkan nilai t tabel untuk unsur besi dan seng masing-masing adalah sebesar 2,130. Kedua metode destruksi tidak berbeda secara nyata untuk penentuan besi, sedangkan untuk penentuan song metode destruksi kering lebih baik daripada metode destruksi basah. The comparation test between wet and dry ashing methods for determination of both iron and zinc contained in leaves of ipomoea plant has been done. Wet ashing was carried out by samples dissolving in 20 mililiters of 3 1 HNO3 H2SO4 mixture at 100 °C for 10 minutes. It was allowed to cool for about 10 minutes, then added 2 mililiters of H202 30 % hereinafter. Samples heating was continued at 200 °C slowly until clear solution approximately formed. Meanwhile, dry ashing was performed by samples ashing in furnace at 400 °C for 3 hours to yield ash. The ash was dissolved in 20 mililiters of 11NO3 dark concentrate. Dissolving process was accelerated by heating it at 200 °C until clear solution formed. Determination of iron and zinc's degree released from both of the two ashing methods was analyzed by flame atomic absorption spectroscopy (FAAS). The experimental research show that wet and dry ashing methods for iron were 2,102 ± 0.052 mg/100 g, with recovery 105.1% and 2.162 ± 0.156 mg/100 g, recovery 106.6%. Meanwhile for zinc were 0.101 ± 0.002 mg/100 g, with recovery 67.8% and 0.255 ± 0.034 mg/100 g, recovery 104.3%. From t student's test in which confidence level 95%, it was acknowledged that t experiment was 0.606 for iron and 7.700 for zinc. Whereas t table from iron and zinc components are 2.130 recpectively. It means that both of ashing methods as the same as good for iron determination. On the other hand, dry ashing method is better than one for iron determination.