David A. Barrett1, Dong-Hyun Kim1. 1: Advanced Materials & Healthcare Technology, School of Pharmacy, University of Nottingham, NG7 2RD, Nottingham, UK.
Improved extraction repeatability and spectral reproducibility for liquid extraction surface analysis – mass spectrometry using superhydrophobic-superhydrophilic patterning Joris Meurs1, Morgan R. Alexander1, Pavel A. Levkin2,3, Simon Widmaier2, Josephine Bunch4, David A. Barrett1, Dong-Hyun Kim1 1
: Advanced Materials & Healthcare Technology, School of Pharmacy, University of Nottingham, NG7 2RD, Nottingham, UK
2
: Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
3
: Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
4
: National Centre of Excellence in Mass Spectrometry Imaging, National Physical Laboratory, TW11 0LW, Teddington, Middlesex, UK
Supplementary material S1: Dimensions of an array feature on the Droplet Microarray S2: Example of correction for signal loss after Savitzky-Golay smoothing S3: LESA-MS spectra for five analytical replicates of control urine extracted from Droplet Microarray (DMA) and glass. S4: Box plots and relative standard deviations for common ions in control urine extracted from glass and Droplet Microarray
Supplementary File 1
Figure S-1: Schematic representation of the dimensions of a spot on the Droplet Microarray. Superhydrophilic spot size: ø: 2.8 mm; superhydrophobic border width: 1.7 mm
Supplementary File 2
Figure S-2: Signal of the base peak (creatinine; m/z 114.0663) before (black) and after (red) SavitzkyGolay smoothing. The ratio (R) is calculated by dividing the base peak intensity before smoothing (Imax,org) by the base peak intensity after smoothing (Imax,smoothed). R will be used as multiplication factor to correct for signal intensity loss due to smoothing.
Figure S-3: Signal intensity before Savitzky-Golay smoothing (black), after Savitzky-Golay smoothing (red) and after signal correction by R multiplication. Left: base peak (creatinine; m/z 114.0663); Right: peak at m/z 163.1231 (17 putative identities). It can be seen that after correction the signal intensity is restored at its original level.
Supplementary File 3
Figure S-4: LESA-MS spectra (m/z 100-400) for analytical replicates of a control urine sample extracted from Droplet Microarray. Spectra normalised to the total ion count (TIC).
Figure S-5: LESA-MS spectra (m/z 100-400) for analytical replicates of a control urine sample extracted from glass. Spectra normalised to the total ion count (TIC).
Supplementary File 3
Figure S-6: Box plots for deviation in signal intensities for common peaks (≥80% detection rate) in LESA-MS spectra obtained after urine extraction (n = 5) from glass and DMA. Data is log transformed and TIC normalised.
Table S-1: Relative standard deviations for signal intensities of common peaks in LESA-MS spectra obtained after urine extraction (n = 5) from glass and DMA. Data is log transformed and TIC normalised. RSD’s were compared using Forkman’s F-test (α = 0.05). Ion (m/z) 112.8959 114.0664 142.9482 158.9222 166.0725 173.0214 173.0576 180.9040 245.1155 255.0630 283.2038 364.9646 368.9591 483.0767
S-6
No. of putative identities (HMDB) 2 9 1 0 14 43 35 0 14 5 6 1 0 9
RSD glass (%) 93.7 93.2 56.2 91.8 91.9 91.8 17.4 91.5 91.8 91.8 91.8 91.8 92.0 91.8
RSD DMA (%) 5.5 1.4 4.2 5.2 5.1 2.9 4.3 5.9 4.3 2.8 2.5 2.9 2.9 3.4
p-value -4 8.12∙10 8.83∙10-5 -3 1.57∙10 6.58∙10-4 -4 7.64∙10 2.57∙10-4 0.0888 5.63∙10-4 -4 5.33∙10 2.35∙10-4 -4 2.01∙10 2.39∙10-4 -4 2.49∙10 3.29∙10-4
