So my data is generated using Waters UPLC/QTOF-MS
I ran the following command in xcms:
xset <- xcmsSet(method="centWave")
xset <- group(xset)
xset@groups
mzmed mzmin mzmax rtmed rtmin rtmax npeaks samples
[1,] 90.52499 90.50587 90.53768 566.7325 493.651 571.501 602 434
[2,] 96.96339 96.96293 96.96393 573.6620 572.318 574.551 432 432
[3,] 97.99267 97.96968 97.99426 570.5130 568.622 573.041 819 432
[4,] 98.51168 98.51125 98.52936 569.8830 480.473 571.088 441 440
[5,] 102.03374 102.03304 102.12967 567.2895 467.341 570.347 544 503
[6,] 111.98470 111.98376 112.03649 571.1140 535.050 572.944 545 462
[7,] 113.96607 113.96540 113.97762 571.2150 493.610 575.702 434 433
[8,] 118.12385 117.93697 118.12470 551.8370 433.981 580.286 1192 432
[9,] 125.98792 125.97683 125.98878 567.3455 490.244 570.640 436 432
[10,] 128.95311 128.95244 128.95365 571.7455 571.056 572.930 432 432
[11,] 141.96116 141.96064 141.98669 571.6450 478.937 572.517 448 432
[12,] 145.93201 145.93138 145.93242 574.9675 573.559 576.317 432 432
[13,] 149.02481 149.02377 149.04653 490.3790 415.157 546.035 568 558
[14,] 158.96294 158.96252 158.96682 572.2490 517.538 573.042 434 432
[15,] 171.15070 171.10154 171.17518 163.7375 105.204 261.115 722 717
[16,] 186.95823 186.95770 186.95874 571.7560 570.904 572.583 432 432
[17,] 187.12794 186.95827 187.15414 206.0160 205.260 263.677 521 516
[18,] 550.63239 550.55762 550.63547 505.1365 498.520 555.740 462 432
[19,] 551.63567 551.55751 551.63963 504.9905 498.503 520.841 442 432
It looks like the program identified 19 peak groups. That means there are 19 analytes identified across multiple samples?
The first analyte is eluting at 566.7325 retention time (median) which has 602 peaks and it appears in 434 samples?
From another thread, I read that I don't have to do retention time correction for UPLC/QTOF. Can anyone tell me why?
Thanks in advance!