Table 1: Categorization of reported elements by group.

Array componentsEssential elementsPotentially toxic elements

(i) Chromium (Cr)(i) Boron (Bo)(i) aluminum (Al) [2628]
(ii) Cobalt (Co)(ii) Calcium (Ca)(ii) Antimony (Sb) [26, 29, 30]
(iii) Copper (Cu)(iii) Lithium (Li)(iii) Arsenic (As) [26, 29, 31, 32]
(iv) Iron (Fe)(iv) Magnesium (Mg)(iv) Barium (Ba) [26, 33]
(v) Manganese (Mn)(v) Phosphorus (P)(v) Cadmium (Cd) [26, 34, 35]
(vi) Molybdenum (Mo)(vi) Potassium (K)(vi) Lead (Pb) [26, 28, 36]
(vii) Nickel (Ni)(vii) Selenium (Se)(vii) Silver (Ag) [26, 37, 38]
(viii) Silicon (Si)(viii) Sodium (Na)(viii) Uranium (U) [26, 39, 40]
(ix) Strontium (Sr)
(x) Sulphur (S)
(xi) Vanadium (Vn)
(xii) Zinc (Zn)