Solving matrix effect, spectral interferences and nonlinearity by generalized standard addition method coupled with radial basis functions-partial least squares: Application to simultaneous determination of drugs in urine

► Presence of nonlinearity was investigated by principal component analysis. ► Generalized standard addition data were analyzed by RBF-PLS. ► Matrix effect, spectral interferences and nonlinearity were solved. ► Drugs were successfully analyzed in complex urine samples.