Sepiolit dolgulu kolonlarda eser element adsorpsiyonu ve diferansiyel puls polarografisi ile tayini

Adsorption of trace elements on sepiolite filled columns and determinations by differential pulse polarography

Özet

Bu çalışmada, sepiolit dolgulu kolonda pH = 2'de $Cu^{2+}$ , $Pb^{2+}$ ve $SeO_3^{2-}$ in adsorpsiyon yoluyla tutulma ve diferansiyel puls polarografisi (DPP) ile tayini işlemi yaklaşık 1g sepiolit ve 5 mL, $l O^{-2}$ M katyon çözeltileri kullanılarak gerçekleştirildi ve kolondan geçen hacmin, sıcaklığın ve sıvı akış hızının etkileri araştırıldı. Ayrıca $SeO_3^{2-}$in kantitatif tayinlerinde girişim yapan $Cu^{2+}$ ve$Pb^{2+}$ den ayrılıp ayrılamayacağı da araştırıldı. Numune yükleme basamağında element geçişinin sıvı hacminin 3/5'inden sonra azaldığı, yıkama basamağında hacmin 2/5'inden sonra element geçişinin çok azaldığı, geri kazanma basamağın da ise hacmin 2/5'inden sonra hızla azaldığı ve hacmin 4/5'inden sonra sabit kaldığı gözlendi. Optimum çalışma sıcaklığı olarak 20°C tespit edildi. Normal sıvı akış hızı, basınç uygulayarak 20 kata kadar arttırıldı ve bunun element adsorpsiyonunu olumsuz etkilemediği gözlendi. Sepiolit tanecik boyutunun değişimi ile sıvı akış hızının hızla değiştiği, bu durumun da$SeO_3^{2-}$in diğer katyonlardan ayrılması açısından olumlu sonuç verdiği gözlendi.

Abstract

In this study, the effects of volume of liquid passing through the column, temperature and flow rate of liquid on the adsorption and determination with DPP of 5 mL, $l O^{-2}$ M$Cu^{2+}$ and $Pb^{2+}$ solutions by approximately l g sepiolite filled columns at pH = 2 were investigated. On the other hand, separability of $SeO_3^{2-}$ from $Cu^{2+}$ ve$Pb^{2+}$ , which these cations causes interferences at quantitative analyses of $SeO_3^{2-}$, was investigated. It was observed that, after the addition of sample solution to the column, elution rate of $Cu^{2+}$, $Pb^{2+}$ and $SeO_3^{2-}$ was reduced after 3/5 of the sample volume was drained. At the washing step, elution rate of the elements was observed to sharply reduced until 2/5 of the sample volume and then the reduction was continued slightly. At the recovery step, elution rates of elements was observed to sharply reduced after 2/5 of the eluent volume and it was levelled off after 4/5 of the eluent volume. 20 °C was determined as the optimum working temperature. It was found that, the adsorption of elements was not negatively affected when normal flow rate was increased up to twenty fold by applying pressure. Finally it was concluded that, liquid flow rate was rapidly changed by changing, the sepiolite particle size. Further, separation of $SeO_3^{2-}$ from the other two cations was a sufficient result from the application stand point.