Effect of different temperatures storage of soil samples on residue of atrazine and diuron herbicides on three soils types in Indonesia

D. Sasongko dan Hendro Santoso M.
Indonesian Sugar Research Institute
Jl.Pahlawan 25 Pasuruan 67126 Indonesia
E-mail : isri@telkom.net

ABSTRACT

Usually soil samples for herbicide residue analysis have to be stored in freeze storage (-7 C) before they were analyzed. However the analysis was facing with a problem i.e : capacity of the freeze storage is to small for a great number of soil samples. Herbicide residue was measured using High Performance Liquid Chromatography (HPLC). The purpose of this study is to investigate the influence of storage temperatures of soil sample on residues of atrazine and diuron on the rate of loss. There were two different temperatures of soil samples storage in this study i.e. –7 C (freeze storage) and 27.5 C (average room temperature).
The results showed that herbicide residue of three soil type in Indonesia (Vertisol, Entisol, Ultisol) in the freeze storage were not decreased for up 15 days after incubation. Contrastly, in the average room temperature, rapid disappearance of the atrazine residues were observed during 9 days (61 – 69 % of the initial dose), while the diuron residue decreased about 21 – 38 % when herbicide residue analysis was conducted 7 days after incubation. Moreover residue of atrazine and diuron in the soil samples stored in the average room temperature were still high (more than 90 % and more than 88 %, respectively) when samples were analysed 5 days after incubation. Based on this fact, soil samples for herbicide residue analysis can be stored in the average room temperature (27.5 C) for 5 days especially for analysing herbicide residue on a great number of soil samples, and the sample must be extracted and analysed within 5 days.