2.6. ICP-OES
ICP-OES is generally used for low to moderate detection limit i.e., 0.1–
100 ppb. The detection limit of elements used in this analysis is shown in
Table 2. In ICP-OES heated Argon plasma is used to excite the concerned
element's atomin the sample and then spectrometer measures the intensity
of the emitted electromagnetic radiations during transformation from
higher to lower energy state at a characteristic wavelength for each element.
The measured intensity is converted into concentration using the
calibration curve of that metal generated using NIST traceable external
multi-element standard solution (Boss and Fredeen, 2004; Gupta and
Mandariya, 2013). Ba, Ca, Cr, Cu, Fe, Mg, Ni and Pb concentrations were
quantified in the indoor air samples with ICP-OES.