Fig. 3: Comparison of the chromatograms and fingerprints of the enriched organosulfate fraction of a representative Handan filter (Handan 1: 18.10.2018, daytime).
From: Unveiling a large fraction of hidden organosulfates in ambient organic aerosol
The x-axis, displaying the retention time (RT (min)), is zoomed into 2.5-28 min of a total method duration of 40 min. There are no peaks outside this time window. The complete CAD chromatogram is shown in Fig. S9. Graph a shows the UHPLC-HRMS data of the enriched OS fraction: RT-m/z plot (circles, right y-axis) and the sum of the extracted ion chromatograms (EIC, dark green line, left y-axis) of all the OSs appearing in the RT-m/z plot. The pie chart illustrates the peak area contribution (%) of the different compound classes to the total detected compound area. Graph b shows the comparison of the UHPLC-CAD chromatograms and the quantified concentrations of individually identified OSs (circles). The three chromatograms show the enriched OS fraction of the Handan 1 filter sample (SPE sample, black line), the corresponding procedural blank of a field filter blank (SPE blank, orange line), and the native extraction (regular liquid extraction technique) of the same ambient filter sample (NE sample, blue line). The circle size represents the organosulfate concentration, determined from the calibration surface (Fig. S4).
