A laboratory study of atrazine transfer from contaminated water during corn steeping process

摘要

Presently, atrazine is one of the most effective and widely used herbicides. As a consequence, soil contamination and thereby surface and ground water contamination, has become a major health and environmental issue. In this study, we investigated the level of contamination of corn bran, germ, endosperm and whole kernels when the wet process steeping water contained 10 $mu$g/L, 30 $mu$g/L, and 50 $mu$g/L atrazine. These contamination levels, chosen for easy detection, demonstrated the potential to estimate the effect of lower water contamination levels on steeped corn grain. The corn kernel capacity to accumulate contamination from the steep water was greatly influenced by the kernel's physical characteristics and the steeping conditions. Due to its high water absorption capacity, the endosperm accumulated the most atrazine from the contaminated water, followed by the germ and bran. This capacity was affected by the steeping temperature and time, the water contamination level, and in some cases, the corn variety.;Percentage contamination of the different components of corn in comparison with the steep water contamination was estimated as follows: contamination of organically grown white corn bran ranged from 1.466 to 4.77%; germ, 0.79 to 14.91%; and endosperm, 26.49 to 68.74% while whole corn contamination ranged from 18.59 to 49.11%. For organically grown yellow corn: bran contamination ranged from 1.34 to 6.3%; germ, from 2.24 to 19.65%; endosperm at 14.55 to 48.95% whole corn was from 14.4 to 58.36% of the contamination level of the steep water.;Sample analysis of yellow corn grown on atrazine treated soil showed no initial atrazine residues. When steeped in naturally contaminated, sand filtered water containing 11.8 $mu$g/L of atrazine, the bran contamination ranged from 3.17 to 14.2%; germ, 6.18 to 21.36%; endosperm, 36.5 to 72.97%; and whole corn, 35.82 to 71.91% of the steep water contamination level.;Atrazine residues were extracted using solid phase extraction (SPE), determined by gas chromatography (GC) equipped with a thermionic specific detector (TSD), and confirmed by gas chromatography/mass spectroscopy (GC/MS).