Evaluation of metal ions and nitrate levels in ground water from private wells in Culturama (State of Mato Grosso do Sul, Brazil) by flame AAS

Nitrate and some metal ion levels (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Ca, K, Mg, and Na) were measured in 31 ground water samples from Culturama, a rural zone of Fatima do Sul city, Brazil. The fast-sequential multi-element flame atomic absorption spectrometry (FS-FAAS) method allowed the determination of these metals with quantification limits ranging from 1.36 mu g L-1 (Mn) -0.71 mg L-1(Ca). Recovery values between 113-116% (Ca), 115-118% (Cd), 105-107% (Co), 98-102% (Cr), 95-98% (Cu), 88-89% (Fe), 84-89% (K), 93-99% (Mg), 97-103% (Mn), 86-93% (Na), and 108-110% (Zn) in three concentration levels were obtained with precisions, expressed as relative standard deviations (RSDs), below 2.2%. The results obtained indicated that concentrations of the elements were generally below the maximum a owed concentration (MAC), ranging from 0.19 to for nitrate and from 22.46 mg L-1 not detected to 40.9 mg L-1 for metal ions analysis. However, the concentrations of Cr, Mn, Cd, Fe, and nitrate in some water samples were above the maximum concentration allowed, set by Portaria MS No. 518/04 (March 25, 2004; Brazilian Regulations). A statistical analysis (as performed by Pearson and Cluster) was used to establish the probable Sources of metal contamination. Activities Such as agriculture and cattle raising, use of septic tanks, and influence of. materials naturally originating in the soil of the Culturama area can all contribute to ground water contamination by these elements.