TABLE 2.

20 most significant mass/charge (m/z) features related to cystic fibrosis and their putative molecular formulae ordered by q-value

m/z#	p-value	FDR-adjusted p-value	Hodges–Lehmann estimator (95% CI)	Putative formula
−151.0247	1.42×10−8	1.15×10−5	1.785 (1.174–2.624)	C4H8O6
−75.0085	1.81×10−8	1.15×10−5	0.991 (0.692–1.557)	C2H4O3
−121.0143	1.95×10−8	1.15×10−5	1.216 (0.803–1.874)	C3H6O5
−122.0195	3.50×10−8	1.54×10−5	1.283 (0.774–1.888)	C(C13)H6O5
+297.0825	1.07×10−6	3.94×10−4	1.110 (0.655–1.643)	C11H20O5S2
+445.1200	1.81×10−6	5.94×10−4	1.197 (0.627–2.033)	C16H20N4O11
−94.0260	2.14×10−6	6.33×10−4	0.960 (0.582–1.309)	H5N3O3
+359.0462	4.02×10−6	1.07×10−3	0.819 (0.502–1.289)	C11H18O9S2
+445.0985	4.43×10−6	1.07×10−3	1.162 (0.584–1.968)	C19H24O8S2
−93.0195	4.73×10−6	1.07×10−3	1.074 (0.637–1.623)	C2H6O4
+357.0490	7.19×10−6	1.52×10−3	1.014 (0.561–1.615)	C11H16O11S
+447.1420	9.56×10−6	1.88×10−3	0.932 (0.476–1.541)	C9H26N4O16
+332.1202	1.19×10−5	1.97×10−3	1.153 (0.639–1.754)	C11H25NO6S2
−105.0188	1.19×10−5	1.97×10−3	0.917 (0.506–1.364)	C3H6O4
+429.0880	1.27×10−5	1.97×10−3	0.922 (0.507–1.472)	C15H24O10S2
+445.1483	1.27×10−5	1.97×10−3	0.809 (0.457–1.338)	C28H20N4S
+188.1645	1.53×10−5	2.25×10−3	−0.799 (−1.153– −0.443)	C10H21NO2
+447.0983	2.34×10−5	3.29×10−3	0.889 (0.464–1.515)	C28H18N2S2
+299.0797	2.48×10−5	3.33×10−3	0.930 (0.548–1.492)	C10H18O8S
+359.0285	2.97×10−5	3.82×10−3	0.872 (0.463–1.436)	C10H14O12S

The entire list including all significant features and all annotated molecular formulae is provided in the table S2, including nine features that could not be assigned with a molecular formula. The intensities were scaled for better readability using distance to median divided by the median absolute deviation. FDR: false discovery rate. ^#: + indicates positive-ionisation mode and − indicates negative-ionisation mode.