Stability of Arsenic During Soil Treatment and Storage

Abstract

There are many studies in the area of identifying and measuring arsenic (As) and its species in soil samples. However, stability of total As, As(V) and As(III) during sample drying and storage has received little attention. The present study evaluates the stability of total As, As(V) and As(III) in four soils with differing agricultural uses and physicochemical properties. Moisture elimination conditions were evaluated, i.e. lyophilization for 1 day vs. drying at 50°C for 3 days, along with different storage conditions, i.e. room temperature for 2 days vs. -20°C for 2 days. The results show that the recovered levels of native As(V) and As(III) are highest using lyophilization and storage at -20°C. Under these optimal conditions, total As content and the levels of As(V) and As(III) remain stable up to 10 days of storage with an error of ±20%.

Thresholds of arsenic toxicity to Eisenia fetida in field-collected agricultural soils exposed to copper mining activities in Chile

“…Lee and Kim (2013) reported that As(III) showed higher toxicity to Eisenia fetida than As(V). In the studied soils, As(V) and As(III) represented 75 712% and 12 7 6% of the total soil arsenic (Vargas et al, 2015). Thus, derived thresholds correspond mainly to As(V).…”

Remediation of Agricultural Soils with Long-Term Contamination of Arsenic and Copper in Two Chilean Mediterranean Areas

“…To prevent volatilization of As during the digestion process, a Teflon stopper with a 30-cm-long glass reflux tube was used (adapted from [40]). Then, total As concentration was determined by hydride generation-atomic fluorescence spectrometry (HG-AFS) under experimental conditions detailed in Vargas et al [4]. On the other hand, the total concentration of Cu was determined by atomic absorption spectroscopy (Flame-AAS).…”

“…To date, most As remediation efforts have focused on rice grown on soils under anaerobic conditions, where As is predominantly like arsenite ((AsO 2 ) − ) [2,3]. However, remediation experiences on crops grown in soils under aerobic conditions, where arsenate ((AsO 4 ) 3− ) is the most common speciation of As (e.g., [4]), are much fewer in number. This knowledge gap is seen in Mediterranean areas such as central Chile despite their global importance due to the high diversity of food produced.…”