Health Risk Assessment and Determination of Some Heavy Metals in Commonly Consumed Traditional Herbal Preparations in Northeast Ethiopia

Table 2

Recovery test results and calibration curve equations (Y = mx + b)^∗ for the determination of heavy metals in herbal preparations.

Analyte	% recovery (%)	Regression equation	R^2	Wavelength (nm)
Pb	85.5–116.4	Y = 1899.4x + 200.23	0.9976	405.7
Cd	81.8–112.6	Y = 15305X + 16275	0.9975	228.8
Cr	86.6–114.8	Y = 13969X + 3289.8	0.9973	425.4
Cu	83.8–117.5	Y = 103051X + 34163	0.9966	324.7

^∗Y = absorbance; m = slope; x = concentration (mg/L); b = intercept.