title: Nondestructive direct determination of heroin in seized illicit street drugs by diffuse reflectance near-infrared spectroscopy.
abstract: A new method has been developed for the fast and nondestructive direct determination of heroin in seized street illicit drugs using partial least-squares regression analysis of diffuse reflectance near-infrared spectra. Data were obtained from untreated samples placed in standard glass chromatography vials. A heterogeneous population of 31 samples, previously analyzed by a reference method, was employed to build the calibration model and to have a separated validation set. Based on the use of zero-order data for a calibration set of 21 samples, after standard normal variate and quadratic linear removed baseline correction (detrending), in the wavelength range from 1111 to 1647 nm, 8 PLS factors were enough to obtain a root-mean-square error of prediction of 1.3% w/w, with a quality coefficient of 10% for the estimation of the accuracy error in the prediction of heroin concentration in unknown samples and a residual predictive deviation of 5.4.
authors.affiliation: Department of Analytical Chemistry, Universitat de Valencia, Edifici Jeroni Muñoz, 50th Dr. Moliner, 46100, Burjassot, Valencia, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Moros
authors.forename: Nieves
authors.initials: N
authors.lastname: Galipienso
authors.forename: Rocío
authors.initials: R
authors.lastname: Vilches
authors.forename: Salvador
authors.initials: S
authors.lastname: Garrigues
authors.forename: Miguel
authors.initials: M
authors.lastname: de la Guardia
mesh_terms: D002138:Calibration; D016000:Cluster Analysis; D003932:Heroin / Q000032:analysis*; D013287:Illicit Drugs / Q000032:analysis*; D016018:Least-Squares Analysis; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D013287:Illicit Drugs; D003932:Heroin