Determination Of Levels Of Some Inorganic Anions In Soil, Amaranthus Hypochondriacus And Amaranthus Cruentus Leaves And Grains From Selected Parts Of Kenya

ABSTRACT

The levels of inorganic anions, nitrate (NO3 - ), chloride (Cl- ), sulphate (SO4 2- ), phosphate (PO4 3- ), fluoride (F- ) and iodide (I - ), in amaranth (Amaranthus hypochondriacus and Amaranthus cruentus) leaves at different stages of maturity (25 days, 50 days and 75 days), grains and soil from four regions (Kenyatta University (KU), Bureti, Kisii and Elgon) of Kenya were quantitatively determined. The levels were determined using spectrophotometric, potentiometric and titrimetric methods. The mean levels of Cl- , SO4 2- , PO4 3- , NO3 - , Fand Iin soils from KU were 1497.93, 2185.33, 933.1350, 1620.06, 66.9583 mg/100 g and 9.94, mg/kg, respectively. The mean levels of the same anions in soils from Bureti were 2733.31, 2135.33, 847.66, 1910.66, 55.17 mg/100 g and 8.00 mg/kg, respectively, while those from Elgon were 1702.20, 1895.79, 1111.36, 1015.55, 79.77 mg/100 g and 10.69 mg/kg, respectively, and in Kisii the means were 1146.54, 1821.60, 828.54, 1739.53, 79.13 mg/100 g and 12.57 mg/kg, respectively. The levels of most anions in leaves of A. hypochondriacus and A. cruentus were not significantly different. The means of levels in leaves of the two species indicated that amaranthus grown in pots at Kenyatta University (KU) had Cl- , SO4 2- , PO4 3- , NO3 - and Fat 673.81, 701.61, 518.62, 871.44 and 7.61 mg/100 g respectively while I- was at 4.29 mg/ kg. Leaves from amaranthus grown in plots in Bureti had mean levels of Cl- , SO4 2- , PO4 3- , NO3 - and Fof 635.24, 750.96, 629.46, 880.99 and 7.22 mg/100 g dry weight, respectively while I- was 3.41 mg/kg. The mean I- level in amaranth leaves grown in plots in Elgon was 2.54 mg/kg while Cl- , SO4 2- , PO4 3- , NO3 - and F- were 503.74, 845.27, 532.36, 495.79 and 9.67 mg/100 g respectively. The mean Cl- , SO4 2- , PO4 3- , NO3 - and Flevel in leaves from plots in Kisii were 595.54, 955.17, 562.34, 819.09 and 8.96 mg/100 g of dry weight respectively, while the mean I - level was 5.26 mg/kg dry weight. Levels of inorganic anions in amaranth leaves at different stages of growth differed significantly. Cl- , SO4 2- , PO4 3- and Flevels in leaves reduced as the plant matured while I - and NO3 - increased with the maturity of the two species of amaranth. Samples of leaves collected in the dry season had mean levels of Cl- , SO4 2- , PO4 3- , NO3 - , Fand Iat 558.36 mg/100 g, 713.53 mg/100 g, 227.25 mg/100 g, 840.38 mg/100 g and 8.42 mg/ 100 g respectively. In the wet season the mean levels of Cl- , SO4 2- , PO4 3- , NO3 - , Fand I- were 645.81 mg/100 g, 912.98 mg/100 g, 894.14 mg/100 g, 693.28 mg/100 g, 8.31 mg/100g and 2.00 mg/kg. The levels of most anions in grains of A. hypochondriacus and A. cruentus were not significantly different. The mean levels of Cl- , SO4 2- , PO4 3- , NO3 - , F - and Iin grains from KU were 469.33,317.36, 378.12, 761.10, 6.39 mg/100 g and 4.7066 mg/kg, respectively. The mean levels of the same anions in grains from Bureti were 466.81, 361.06, 457.10, 693.36, 7.06 mg/100 g and 3.42 mg/kg, respectively, while those from Elgon were 263.41, 435.63, 218.54, 541.21, 3.70 mg/100 g and 2.96 mg/kg, respectively, and in Kisii the means were 232.70, 377.28, 379.08, 1294.10, 4.47 mg/100 g and 6.05 mg/kg, respectively. The levels of all inorganic anions determined were found to be within the allowed daily intake (ADI) values. Based on the results of this study, it is recommended that leaves and grains from both species of amaranthus grown in most regions in Kenya may be consumed for nutritional requirements. The consumption of between 250 g and 300 g of fresh amaranthus leaves is sufficient to provide the required daily intake of all the anions considered in this study for all healthy individuals.