Rapid screening for detection and differentiation of detergent powder adulteration in infant milk formula by LC–MS Manjun Tay, Guihua Fang, Poh Ling Chia, Sam Fong Yau Li Forensic Science International Volume 232, Issue 1, Pages 32-39 (October 2013) DOI: 10.1016/j.forsciint.2013.06.013 Copyright © 2013 Elsevier Ireland Ltd Terms and Conditions
Fig. 1 PCA score plots (centering) of 0–20% D1 adulterated in M2 samples acquired by LC-Qtrap in 12min LC run time under (a) negative electrospray ionization with R2(cum) and Q2(cum) values of 0.990 and 0.958 respectively], (b) positive electrospray ionization with R2(cum) and Q2(cum) values of 0.954 and 0.903 respectively. The numbers represent % adulteration level and ‘R’ represents samples for inter-day reproducibility test. Forensic Science International 2013 232, 32-39DOI: (10.1016/j.forsciint.2013.06.013) Copyright © 2013 Elsevier Ireland Ltd Terms and Conditions
Fig. 2 PCA score plots (centering) of M1 samples adulterated with 20% of various detergent brands by LC-Qtrap, 25min LC run time under (a) negative electrospray ionization and (b) positive electrospray ionization. Forensic Science International 2013 232, 32-39DOI: (10.1016/j.forsciint.2013.06.013) Copyright © 2013 Elsevier Ireland Ltd Terms and Conditions
Fig. 3 Contribution plot of the difference between adulterated and pure M3 samples analyzed by negative electrospray ionization LC-Qtrap, 25min LC run time. Forensic Science International 2013 232, 32-39DOI: (10.1016/j.forsciint.2013.06.013) Copyright © 2013 Elsevier Ireland Ltd Terms and Conditions
Fig. 4 (a) 3D PCA score plot (centering) and (b) zoomed-in image of the boxed up region (left) of pure M1 and adulterated M1 samples with 20% various detergent brands analyzed by negative electrospray ionization LC-QTOF–MS in 25min LC run time. Forensic Science International 2013 232, 32-39DOI: (10.1016/j.forsciint.2013.06.013) Copyright © 2013 Elsevier Ireland Ltd Terms and Conditions
Fig. 5 Total ion chromatograms of pure M1 and adulterated samples containing 20% of various detergent brands by negative electrospray ionization LC-QTOF–MS, 25min run time. Forensic Science International 2013 232, 32-39DOI: (10.1016/j.forsciint.2013.06.013) Copyright © 2013 Elsevier Ireland Ltd Terms and Conditions
Fig. 6 MS/MS spectrum of m/z 325.1843 ion in M1 sample adulterated with 20% D1 analyzed by negative electrospray ionization LC-QTOF–MS, 25min LC run time. Forensic Science International 2013 232, 32-39DOI: (10.1016/j.forsciint.2013.06.013) Copyright © 2013 Elsevier Ireland Ltd Terms and Conditions