y- intercept means
The point at which the curve touches the y-axis is called intecept.[ extrapolate the curve ]
If the concentrations and Absorbances are exactly linear(r^2 = 1), the value of y-intercept is zero, It indicates there is no deviation of the linear curve.
if you get y-intercept other than zero, it clearly indicates there is a deviation. that deviation must be estimated by the formula as stated above.
that is expressed in % also.
(y-intercept x 100)/ response at 100%
% y -intercept conventionally acceptable.
Impurities : +/-5%
Bujji Reddy Kanchi.