Heavy metals

Wavelength (nm)

Calibration curve

Determination coefficient (R2)

Regression coefficient (r)

Detection limit (mg/L)

Cd

228.8 nm

y = 0.3497x − 0.0019

0.999

0.999

0.03

Cu

324.8 nm

y = 0.1179x − 0.0015

0.999

0.999

0.03

Ni

232.0 nm

y = 0.0880x − 0.0011

0.996

0.997

0.05

Pb

217.0 nm

y = 0.0484x − 0.0008

0.999

0.999

0.03

Zn

213.9 nm

y = 0.3917x + 0.0377

0.996

0.997

0.50