# XCMS peak detection 臺大生醫電資所林柏嶢 Installation --- ### Install R 1. Download the most recent version of R. The R FAQs and the R Installation and Administration Manual contain detailed instructions for installing R on various platforms (Linux, OS X, and Windows being the main ones). 2. Start the R program; on Windows and OS X, this will usually mean double-clicking on the R application, on UNIX-like systems, type “R” at a shell prompt. 3. As a first step with R, start the R help browser by typing help.start() in the R command window. For help on any function, e.g. the “mean” function, type ? mean. ### Install Bioconductor Packages To install core packages, type the following in an R command window: ```R if (!require("BiocManager", quietly = TRUE)) install.packages("BiocManager") BiocManager::install() ``` To install "XCMS" package, start R (version "4.3") and enter: ```R if (!require("BiocManager", quietly = TRUE)) install.packages("BiocManager") BiocManager::install("xcms") ``` To view documentation for the version of "XCMS" package installed in your system, start R and enter: ```R browseVignettes("xcms") ``` choose "LCMS data preprocessing and analysis with xcms": ![](https://i.imgur.com/GdXYd15.png) LCMS data preprocessing and analysis with xcms --- ### Data Import ```R library(xcms) library(RColorBrewer) library(magrittr) library(SummarizedExperiment) library(readMzXmlData) library(magrittr) library(Spectra) ``` To install "MSnbase" package, start R (version "4.3") and enter: ```R if (!require("BiocManager", quietly = TRUE)) install.packages("BiocManager") BiocManager::install("MSnbase") ``` Move direction of "File.mzXML" under the package "readMzXmlData" Get the data file in msdata package ```R file <- system.file("File_name.mzXML", package = "readMzXmlData") raw_data <- readMSData(file, mode = "onDisk") ``` ## TIC 箱型分布圖 ```R tc <- split(tic(raw_data), f = fromFile(raw_data)) boxplot(tc, col = group_colors[raw_data$sample_group], ylab = "intensity", main = "Total ion current") ``` ![](https://hackmd.io/_uploads/rk1Ho1et2.png) ## TIC圖 ```R ## Get the base peak chromatograms. This reads data from the files. bpis <- chromatogram(raw_data, aggregationFun = "sum") ## Plot all chromatograms. plot(bpis) ``` ![](https://hackmd.io/_uploads/r1jriJlY2.png) ## EIC圖(rtr = 5450-5480) ```R ## Define the rt and m/z range of the peak area rtr <- c(5450, 5480) mzr <- c(77, 1154) ## extract the chromatogram chr_raw <- chromatogram(raw_data, mz = mzr, rt = rtr) plot(chr_raw) ``` ![](https://hackmd.io/_uploads/By0wskgFh.png) ![](https://hackmd.io/_uploads/HJn8i1gK2.png) ## peak原始數據視覺化 ```R raw_data %>% filterRt(rt = rtr) %>% filterMz(mz = mzr) %>% plot(type = "XIC") ``` ![](https://hackmd.io/_uploads/S1xFoklt3.png) ## 利用centwave找peak ```R > xchr <- findChromPeaks(chr_raw, param = CentWaveParam(snthresh = 2)) Warning message: In serialize(data, node$con) : 'package:stats' may not be available when loading > head(chromPeaks(xchr)) rt rtmin rtmax into intb maxo sn row column [1,] 1126.53 1106.31 1149.35 7161675031 595512651 195413094 6 1 1 [2,] 1314.52 1291.76 1337.42 10930483834 4032942319 354192967 62 1 1 [3,] 1691.99 1665.48 1723.95 12241405027 2589597150 243151651 8 1 1 [4,] 1800.53 1777.92 1824.01 11103091494 3377281372 336810499 15 1 1 [5,] 1892.26 1868.64 1916.15 9745887872 2185146715 272231009 24 1 1 > chromPeakData(xchr) DataFrame with 5 rows and 4 columns ms_level is_filled row column <integer> <logical> <integer> <integer> 1 1 FALSE 1 1 2 1 FALSE 1 1 3 1 FALSE 1 1 4 1 FALSE 1 1 5 1 FALSE 1 1 ``` ## 標註peak並設置sn ratio ```R sample_colors <- group_colors[xchr$sample_group] plot(xchr, col = sample_colors, peakBg = sample_colors[chromPeaks(xchr)[, "column"]]) ``` ![](https://hackmd.io/_uploads/rkw5j1lFn.png) ## 信號處理 ```R > cwp <- CentWaveParam(peakwidth = c(20, 80), noise = 5000, prefilter = c(6, 5000)) > xdata <- findChromPeaks(raw_data, param = cwp) > head(chromPeaks(xdata)) mz mzmin mzmax rt rtmin rtmax into intb maxo sn sample CP00001 214.78322 214.78291 214.78360 32.5736 32.2066 67.3885 1476974.9 1419130.7 98881.38 11 1 CP00002 153.98920 153.98852 153.98988 55.6840 50.0551 66.8369 314565.6 314316.7 42804.64 121 1 CP00003 259.83954 259.83926 259.83981 54.7848 50.7856 60.3323 414399.9 414390.8 75422.00 75421 1 CP00004 408.87648 408.87585 408.87692 55.6840 50.4209 65.8763 135063.3 135052.1 19344.90 19344 1 CP00005 80.96504 80.96494 80.96511 56.9408 40.0861 71.0318 183342.5 179587.9 23295.86 21 1 CP00006 98.96429 98.96423 98.96435 56.9408 51.3237 67.3885 231917.6 231465.8 40222.71 105 1 > chromPeakData(xdata) DataFrame with 10269 rows and 2 columns ms_level is_filled <integer> <logical> CP00001 1 FALSE CP00002 1 FALSE CP00003 1 FALSE CP00004 1 FALSE CP00005 1 FALSE ... ... ... CP10265 1 FALSE CP10266 1 FALSE CP10267 1 FALSE CP10268 1 FALSE CP10269 1 FALSE ``` ## 根據一個樣品的保留時間確定 m/z ```R plotChromPeaks(xdata) ``` ![](https://hackmd.io/_uploads/Sktl21lF3.png) ## peak資訊 ```R > chr_ex <- chromatogram(xdata, mz = mzr, rt = rtr) > chromPeaks(chr_ex) mz mzmin mzmax rt rtmin rtmax into intb maxo sn sample row CP00573 414.02662 414.02527 414.02899 1020.00 1008.76 1029.56 3.980135e+05 3.979955e+05 48335.41 48334 1 1 CP00574 403.99750 403.99600 403.99963 1020.69 1020.34 1031.81 2.264889e+05 2.264787e+05 42429.03 43276 1 1 CP00575 429.04537 429.04416 429.05051 1020.69 1007.20 1047.35 5.317195e+05 5.300225e+05 47464.35 77 1 1 CP00576 166.01755 166.01700 166.01790 1020.00 1000.22 1039.48 1.441003e+06 1.360571e+06 96657.29 25 1 1 CP00577 428.04210 428.04187 428.04504 1020.00 1004.57 1039.48 5.503697e+06 5.502905e+06 375569.09 993 1 1 CP00578 240.16063 240.15900 240.16212 1032.87 1021.89 1033.24 1.770656e+05 1.762967e+05 42124.66 40 1 1 CP00579 258.17107 258.17038 258.17142 1039.48 1019.65 1050.35 3.372856e+05 3.342481e+05 32405.90 26 1 1 CP00580 198.14935 198.14899 198.15018 1038.27 1018.44 1055.82 8.549324e+05 8.193957e+05 54138.33 17 1 1 CP00583 242.98615 242.98602 242.98639 1062.95 1050.01 1076.65 1.812556e+06 1.812530e+06 140725.98 140725 1 1 CP00586 308.15838 308.15665 308.16071 1103.47 1088.97 1124.84 9.010263e+05 8.973622e+05 58826.87 57 1 1 CP00589 291.98841 291.98666 291.98948 1102.76 1087.10 1122.45 5.370857e+06 5.370263e+06 341712.91 846 1 1 CP00591 348.91893 348.91529 348.92670 1126.53 1126.01 1142.99 4.079507e+06 3.995540e+06 981941.40 39 1 1 CP00592 720.86980 720.86450 720.87311 1127.05 1117.27 1136.45 4.369601e+05 4.369437e+05 61562.95 61562 1 1 CP00593 756.94192 756.93610 756.94598 1126.01 1116.21 1136.45 8.600201e+05 8.600002e+05 92406.80 92406 1 1 CP00594 430.94348 430.94101 430.94492 1126.53 1114.15 1138.75 6.296213e+05 6.295987e+05 55074.79 55074 1 1 CP00595 98.95521 98.95474 98.95560 1126.01 1110.69 1145.42 4.874968e+05 4.863716e+05 45978.25 103 1 1 CP00596 348.76226 348.75739 348.76721 1127.05 1114.15 1139.43 8.365823e+05 8.365583e+05 63347.85 63347 1 1 CP00597 349.11729 349.11319 349.12140 1127.05 1114.15 1140.97 8.831030e+05 8.801696e+05 62840.95 46 1 1 CP00598 351.93906 351.93823 351.94016 1126.53 1111.57 1142.48 1.143236e+06 1.143209e+06 88101.78 88101 1 1 CP00599 433.91701 433.91580 433.91794 1126.53 1113.13 1142.48 1.321640e+06 1.321613e+06 87241.27 87240 1 1 CP00600 79.95658 79.95643 79.95686 1127.05 1104.49 1150.03 2.899080e+06 2.857638e+06 183229.51 77 1 1 CP00601 348.86739 348.86096 348.87067 1126.53 1112.07 1145.76 3.357715e+06 3.356498e+06 269803.62 498 1 1 CP00602 349.01264 349.00956 349.01840 1126.53 1110.69 1144.05 3.294166e+06 3.288988e+06 241107.26 140 1 1 CP00603 87.23659 87.23653 87.23666 1126.53 1112.79 1142.99 1.692920e+06 1.692890e+06 111850.01 111849 1 1 CP00604 284.18659 284.18509 284.18726 1139.78 1128.29 1155.30 6.648265e+05 6.648036e+05 49720.16 49719 1 1 CP00605 350.93636 350.93546 350.93673 1126.53 1109.27 1146.94 2.549128e+07 2.548618e+07 1682215.04 1491 1 1 CP00606 349.94329 349.94315 349.94348 1126.53 1108.24 1146.45 2.919620e+07 2.919094e+07 1904561.25 1620 1 1 CP00607 298.20260 298.20163 298.20331 1162.70 1152.84 1175.55 3.332743e+05 3.332550e+05 36657.47 36656 1 1 CP00608 307.15511 307.15311 307.15717 1103.81 1079.77 1128.29 5.557237e+06 5.135880e+06 302354.59 27 1 1 CP00609 366.98108 366.98044 366.98175 1169.47 1158.05 1180.52 4.419095e+05 4.418891e+05 35493.66 35493 1 1 CP00610 717.99938 717.99622 718.00079 1169.97 1162.36 1176.93 2.077730e+05 2.077601e+05 33386.45 33385 1 1 CP00611 168.98168 168.98014 168.98249 1169.47 1155.30 1186.08 2.858047e+06 2.856290e+06 245717.51 269 1 1 CP00612 185.98784 185.98756 185.98824 1169.11 1158.05 1178.98 4.752630e+05 4.752429e+05 44257.94 44257 1 1 CP00613 370.95582 370.95520 370.95618 1169.97 1158.95 1179.69 9.372729e+05 9.372530e+05 97956.73 97956 1 1 CP00614 413.94538 413.94449 413.94644 1168.42 1155.98 1180.89 8.302701e+05 8.302477e+05 73932.06 73931 1 1 CP00615 103.97647 103.97636 103.97659 1168.42 1155.98 1180.89 8.965597e+05 8.965360e+05 80089.05 80088 1 1 CP00616 410.97115 410.97049 410.97177 1169.97 1156.33 1183.15 8.049183e+05 8.048945e+05 69645.88 69645 1 1 CP00617 659.94683 659.94464 659.94830 1170.85 1158.59 1180.52 1.245739e+06 1.245717e+06 131496.53 131496 1 1 CP00618 716.99709 716.99512 716.99835 1169.47 1158.05 1183.99 1.917872e+06 1.917849e+06 172905.83 172905 1 1 CP00619 168.92958 168.92790 168.93097 1170.34 1157.52 1182.81 5.563983e+05 5.563743e+05 41604.96 41604 1 1 CP00620 328.96786 328.96741 328.96838 1169.97 1155.64 1185.03 1.807909e+06 1.807883e+06 140810.28 140809 1 1 CP00621 680.92594 680.92438 680.92682 1169.97 1158.05 1181.40 2.045635e+06 2.045612e+06 198440.16 198439 1 1 CP00622 285.98103 285.98071 285.98141 1170.34 1156.67 1182.81 1.142218e+06 1.142192e+06 86813.69 86813 1 1 CP00623 168.96507 168.96414 168.96590 1170.34 1154.25 1190.15 2.467367e+06 2.465926e+06 165376.64 317 1 1 CP00624 101.00195 101.00185 101.00205 1169.97 1154.96 1187.43 1.618048e+06 1.618018e+06 111016.45 111015 1 1 CP00625 168.99620 168.99400 168.99680 1169.97 1152.84 1191.17 3.882694e+06 3.875967e+06 496143.33 423 1 1 CP00626 658.94379 658.94305 658.94434 1170.85 1156.33 1186.41 1.048224e+07 1.048221e+07 976949.81 976949 1 1 CP00627 242.18802 242.18717 242.19018 1186.08 1172.26 1202.37 6.103078e+06 5.980782e+06 780799.51 26 1 1 CP00628 169.01346 169.01226 169.01480 1170.34 1149.00 1190.83 2.518832e+06 2.500480e+06 172958.46 108 1 1 CP00629 431.96293 431.96164 431.96362 1174.14 1159.59 1189.48 1.260691e+06 1.260663e+06 88207.61 88207 1 1 CP00630 323.99443 323.99377 323.99481 1176.26 1162.00 1190.83 1.462192e+06 1.462165e+06 108070.09 108069 1 1 CP00631 428.16417 428.16257 428.16541 1183.99 1172.63 1201.53 3.171272e+05 3.151399e+05 36527.89 44 1 1 CP00632 507.34137 507.33932 507.34253 1185.40 1176.60 1193.79 2.885974e+05 2.885827e+05 38962.83 38962 1 1 CP00633 382.13834 382.13760 382.13913 1186.08 1173.30 1199.44 2.323951e+05 2.316373e+05 29112.38 47 1 1 CP00634 146.98742 146.98728 146.98749 1170.34 1153.37 1191.68 4.755749e+06 4.746197e+06 314668.94 277 1 1 CP00635 280.14940 280.14893 280.14990 1186.41 1176.60 1194.30 2.392216e+05 2.392080e+05 31136.39 31135 1 1 CP00636 301.13791 301.13733 301.13852 1185.74 1174.14 1196.61 3.531324e+05 3.528060e+05 36053.77 87 1 1 CP00637 242.27928 242.27608 242.28169 1186.08 1173.64 1197.63 7.802767e+05 7.802552e+05 60103.21 60102 1 1 CP00638 400.16530 400.16422 400.16635 1184.52 1171.73 1199.81 4.613018e+05 4.599824e+05 43206.94 59 1 1 CP00639 169.99267 169.99255 169.99282 1169.97 1151.23 1191.17 8.567885e+06 8.561490e+06 492848.47 432 1 1 CP00641 265.16120 265.16083 265.16150 1185.40 1173.64 1198.31 6.633692e+05 6.633482e+05 58462.39 58461 1 1 CP00642 242.07352 242.06995 242.07629 1185.40 1174.14 1198.92 8.103680e+05 8.103461e+05 62020.33 62019 1 1 CP00643 278.15322 278.15259 278.15356 1186.08 1173.64 1197.29 1.103253e+06 1.103230e+06 97086.02 97085 1 1 CP00644 325.18255 325.18192 325.18448 1186.08 1172.63 1206.92 6.704784e+05 6.690653e+05 50210.59 81 1 1 CP00645 406.18275 406.18188 406.18372 1186.08 1173.64 1201.53 4.606509e+05 4.600712e+05 38685.07 89 1 1 CP00646 284.97785 284.97770 284.97797 1169.97 1151.76 1190.83 2.235685e+07 2.235007e+07 1585915.81 1086 1 1 CP00647 118.99244 118.99236 118.99252 1170.34 1148.63 1191.68 5.829694e+06 5.501833e+06 339145.69 47 1 1 CP00648 302.13153 302.13113 302.13193 1185.40 1172.26 1199.44 1.030116e+06 1.030090e+06 80027.01 80026 1 1 CP00649 422.14753 422.14633 422.14853 1185.74 1170.85 1206.92 6.003514e+05 6.000055e+05 47850.74 166 1 1 CP00650 340.14590 340.14389 340.14799 1185.40 1171.22 1200.84 1.253072e+06 1.253044e+06 89242.76 89242 1 1 CP00651 346.16134 346.16071 346.16193 1185.74 1170.34 1204.30 1.117220e+06 1.117191e+06 77051.44 77050 1 1 CP00652 242.13451 242.13301 242.13671 1185.40 1169.47 1206.40 3.656942e+06 3.656317e+06 245186.15 554 1 1 CP00653 134.98744 134.98735 134.98757 1170.34 1150.03 1191.17 1.408627e+07 1.407880e+07 841154.22 807 1 1 CP00654 225.14960 225.14888 225.15047 1185.40 1164.02 1206.06 1.734845e+06 1.698659e+06 107788.79 28 1 1 CP00655 242.21762 242.21589 242.22054 1185.40 1170.34 1206.40 3.747425e+06 3.737660e+06 246075.50 127 1 1 CP00656 327.15367 327.15341 327.15427 1185.40 1170.85 1205.72 1.758679e+06 1.758647e+06 119522.83 119522 1 1 column CP00573 1 CP00574 1 CP00575 1 CP00576 1 CP00577 1 CP00578 1 CP00579 1 CP00580 1 CP00583 1 CP00586 1 CP00589 1 CP00591 1 CP00592 1 CP00593 1 CP00594 1 CP00595 1 CP00596 1 CP00597 1 CP00598 1 CP00599 1 CP00600 1 CP00601 1 CP00602 1 CP00603 1 CP00604 1 CP00605 1 CP00606 1 CP00607 1 CP00608 1 CP00609 1 CP00610 1 CP00611 1 CP00612 1 CP00613 1 CP00614 1 CP00615 1 CP00616 1 CP00617 1 CP00618 1 CP00619 1 CP00620 1 CP00621 1 CP00622 1 CP00623 1 CP00624 1 CP00625 1 CP00626 1 CP00627 1 CP00628 1 CP00629 1 CP00630 1 CP00631 1 CP00632 1 CP00633 1 CP00634 1 CP00635 1 CP00636 1 CP00637 1 CP00638 1 CP00639 1 CP00641 1 CP00642 1 CP00643 1 CP00644 1 CP00645 1 CP00646 1 CP00647 1 CP00648 1 CP00649 1 CP00650 1 CP00651 1 CP00652 1 CP00653 1 CP00654 1 CP00655 1 CP00656 1 [ reached getOption("max.print") -- omitted 388 rows ] ``` ## 自動突出顯示識別出的peak ```R plot(chr_ex, peakType = "rectangle", peakBg = NA) ``` ![](https://hackmd.io/_uploads/r1Q13ygt3.png) ## 以表格呈現選定的 m/z 和保留時間範圍內識別出的peak ```R if (!require("pander", quietly = TRUE)) install.packages("pander") pander::install() pander(chromPeaks(xdata, mz = mzr, rt = rtr), caption = paste("Identified chromatographic peaks in a selected ", "m/z and retention time range.")) Table: Identified chromatographic peaks in a selected m/z and retention time range. (continued below) --------------------------------------------------------- &nbsp; intb maxo sn sample -------------- ----------- ----------- --------- -------- **CP00546** 324423 37036 106 1 **CP00547** 135890 11490 11489 1 **CP00550** 398440 42227 42226 1 **CP00551** 389086 58121 58120 1 **CP00552** 358991 33551 30 1 **CP00553** 535904 52630 127 1 **CP00554** 306187 61348 61347 1 ``` # (07/17update)LC-MS/MS data analysis with xcms ## Data import: ```R $ dda_file <- system.file("new_cali_std_150.mzXML", package = "readMzXmlData") $ dda_data <- readMSData(dda_file, mode = "onDisk") ``` ## The number of spectra for each MS level: ```R $ table(msLevel(dda_data)) 1 2 13593 7051 ``` ## Extract the precursor m/z and show the first 6 elements: ```R $ dda_data %>% filterMsLevel(2L) %>% precursorMz() %>% head() F1.S00002 F1.S00003 F1.S00004 F1.S00017 F1.S00020 F1.S00032 156.01245 212.11079 212.04181 212.10562 141.00084 96.96004 ``` ## Extract the intensity of the precursor ion: ```R $ dda_data %>% filterMsLevel(2L) %>% precursorIntensity() %>% head() F1.S00002 F1.S00003 F1.S00004 F1.S00017 F1.S00020 F1.S00032 2747194.3 78450596.6 78450596.6 74885656.6 590244.7 284270.8 ``` ## Chromatographic peak detection on the MS level 1 data: ```R $ cwp <- CentWaveParam(snthresh = 5, noise = 100, ppm = 10, peakwidth = c(3, 30)) $ dda_data <- findChromPeaks(dda_data, param = cwp) Detecting mass traces at 10 ppm ... OK Detecting chromatographic peaks in 248839 regions of interest ... OK: 9083 found. ``` ## MS2 spectra with their precursor m/z and retention time within the rt and m/z range of the chromatographic peak: ```R $ dda_spectra <- chromPeakSpectra(dda_data, msLevel = 2L, return.type = "Spectra") $ dda_spectra MSn data (Spectra) with 1076 spectra in a MsBackendMzR backend: msLevel rtime scanIndex <integer> <numeric> <integer> F1.S00171 2 56.7721 171 F1.S00220 2 69.7215 220 F1.S00171 2 56.7721 171 F1.S00220 2 69.7215 220 F1.S00170 2 56.6784 170 ... ... ... ... F1.S20516 2 5680.51 20516 F1.S20594 2 5690.98 20594 F1.S20520 2 5681.25 20520 F1.S20599 2 5691.79 20599 F1.S20615 2 5694.22 20615 ... 38 more variables/columns. file(s): new_cali_std_150.mzXML ``` ## Evaluate the full MS1 signal at the peak’s apex position: ```R $ dda_spectra$peak_id [1] "CP0433" "CP0434" "CP0436" "CP0437" "CP0438" "CP0439" "CP0441" "CP0494" "CP0495" "CP0502" "CP0523" "CP0547" [13] "CP0590" "CP0605" "CP0609" "CP0627" "CP0654" "CP0667" "CP0673" "CP0683" "CP0693" "CP0699" "CP0835" "CP0858" [25] "CP0873" "CP0873" "CP0874" "CP0875" "CP0877" "CP0878" "CP0954" "CP0954" "CP0955" "CP1063" "CP1063" "CP1063" [37] "CP1064" "CP1081" "CP1081" "CP1082" "CP1083" "CP1104" "CP1137" "CP1142" "CP1153" "CP1162" "CP1163" "CP1171" [49] "CP1171" "CP1172" "CP1175" "CP1175" "CP1176" "CP1184" "CP1239" "CP1240" "CP1240" "CP1241" "CP1244" "CP1277" [61] "CP1277" "CP1277" "CP1286" "CP1286" "CP1286" "CP1286" "CP1287" "CP1287" "CP1287" "CP1288" "CP1289" "CP1290" [73] "CP1292" "CP1293" "CP1294" "CP1295" "CP1297" "CP1299" "CP1302" "CP1303" "CP1426" "CP1426" "CP1429" "CP1429" [85] "CP1438" "CP1438" "CP1458" "CP1459" "CP1460" "CP1463" "CP1463" "CP1513" "CP1520" "CP1522" "CP1522" "CP1523" [97] "CP1613" "CP1616" "CP1617" "CP1635" "CP1636" "CP1637" "CP1637" "CP1638" "CP1639" "CP1640" "CP1641" "CP1641" [109] "CP1642" "CP1643" "CP1643" "CP1644" "CP1702" "CP1702" "CP1703" "CP1708" "CP1781" "CP1781" "CP1781" "CP1865" [121] "CP1865" "CP1865" "CP1866" "CP1887" "CP1891" "CP1891" "CP1891" "CP1892" "CP2032" "CP2033" "CP2053" "CP2053" [133] "CP2054" "CP2055" "CP2064" "CP2065" "CP2067" "CP2080" "CP2080" "CP2081" "CP2082" "CP2096" "CP2096" "CP2096" [145] "CP2097" "CP2098" "CP2098" "CP2099" "CP2111" "CP2111" "CP2111" "CP2112" "CP2120" "CP2120" "CP2120" "CP2120" [157] "CP2121" "CP2122" "CP2145" "CP2201" "CP2205" "CP2208" "CP2208" "CP2210" "CP2327" "CP2329" "CP2330" "CP2330" [169] "CP2330" "CP2332" "CP2333" "CP2334" "CP2340" "CP2340" "CP2340" "CP2341" "CP2342" "CP2344" "CP2345" "CP2346" [181] "CP2347" "CP2355" "CP2355" "CP2356" "CP2363" "CP2363" "CP2365" "CP2464" "CP2465" "CP2473" "CP2473" "CP2473" [193] "CP2474" "CP2475" "CP2481" "CP2524" "CP2532" "CP2532" "CP2532" "CP2533" "CP2534" "CP2605" "CP2605" "CP2605" [205] "CP2607" "CP2608" "CP2619" "CP2621" "CP2625" "CP2645" "CP2645" "CP2647" "CP2648" "CP2652" "CP2655" "CP2675" [217] "CP2677" "CP2684" "CP2684" "CP2684" "CP2686" "CP2688" "CP2702" "CP2711" "CP2711" "CP2711" "CP2712" "CP2753" [229] "CP2771" "CP2772" "CP2772" "CP2774" "CP2863" "CP2890" "CP2890" "CP2890" "CP2891" "CP2897" "CP2907" "CP2907" [241] "CP2908" "CP2909" "CP2910" "CP2911" "CP2912" "CP2912" "CP2912" "CP2913" "CP2913" "CP2915" "CP2915" "CP2916" [253] "CP2918" "CP2918" "CP2918" "CP2921" "CP2923" "CP2923" "CP2923" "CP2924" "CP2930" "CP2930" "CP2972" "CP2972" [265] "CP2972" "CP2974" "CP2976" "CP2986" "CP2986" "CP2986" "CP2986" "CP2987" "CP2987" "CP2987" "CP2988" "CP2990" [277] "CP2991" "CP2997" "CP2998" "CP2999" "CP3012" "CP3012" "CP3012" "CP3034" "CP3035" "CP3091" "CP3093" "CP3093" [289] "CP3093" "CP3094" "CP3096" "CP3110" "CP3110" "CP3112" "CP3165" "CP3165" "CP3166" "CP3175" "CP3176" "CP3178" [301] "CP3236" "CP3293" "CP3293" "CP3293" "CP3294" "CP3296" "CP3297" "CP3304" "CP3306" "CP3314" "CP3316" "CP3359" [313] "CP3359" "CP3359" "CP3359" "CP3360" "CP3362" "CP3374" "CP3427" "CP3427" "CP3427" "CP3427" "CP3428" "CP3429" [325] "CP3429" "CP3431" "CP3432" "CP3433" "CP3434" "CP3435" "CP3435" "CP3446" "CP3446" "CP3446" "CP3446" "CP3447" [337] "CP3448" "CP3448" "CP3463" "CP3474" "CP3474" "CP3475" "CP3497" "CP3497" "CP3498" "CP3500" "CP3501" "CP3502" [349] "CP3503" "CP3503" "CP3503" "CP3504" "CP3505" "CP3506" "CP3506" "CP3507" "CP3514" "CP3514" "CP3514" "CP3514" [361] "CP3547" "CP3547" "CP3560" "CP3590" "CP3590" "CP3590" "CP3590" "CP3591" "CP3626" "CP3637" "CP3637" "CP3685" [373] "CP3685" "CP3689" "CP3713" "CP3715" "CP3715" "CP3715" "CP3717" "CP3718" "CP3724" "CP3724" "CP3724" "CP3724" [385] "CP3726" "CP3728" "CP3729" "CP3730" "CP3732" "CP3734" "CP3740" "CP3775" "CP3777" "CP3786" "CP3786" "CP3787" [397] "CP4055" "CP4057" "CP4057" "CP4057" "CP4058" "CP4059" "CP4059" "CP4059" "CP4059" "CP4060" "CP4062" "CP4064" [409] "CP4064" "CP4066" "CP4086" "CP4145" "CP4145" "CP4147" "CP4167" "CP4167" "CP4167" "CP4168" "CP4169" "CP4170" [421] "CP4245" "CP4254" "CP4254" "CP4254" "CP4254" "CP4254" "CP4255" "CP4255" "CP4303" "CP4304" "CP4306" "CP4385" [433] "CP4385" "CP4395" "CP4395" "CP4395" "CP4397" "CP4513" "CP4513" "CP4514" "CP4516" "CP4548" "CP4549" "CP4554" [445] "CP4554" "CP4554" "CP4555" "CP4556" "CP4557" "CP4644" "CP4877" "CP4972" "CP4973" "CP4976" "CP5044" "CP5052" [457] "CP5060" "CP5135" "CP5159" "CP5191" "CP5192" "CP5194" "CP5204" "CP5205" "CP5206" "CP5226" "CP5226" "CP5268" [469] "CP5404" "CP5404" "CP5416" "CP5416" "CP5417" "CP5435" "CP5473" "CP5505" "CP5521" "CP5523" "CP5537" "CP5548" [481] "CP5555" "CP5580" "CP5583" "CP5587" "CP5589" "CP5596" "CP5598" "CP5608" "CP5616" "CP5616" "CP5616" "CP5618" [493] "CP5619" "CP5625" "CP5632" "CP5634" "CP5677" "CP5690" "CP5690" "CP5691" "CP5696" "CP5698" "CP5708" "CP5709" [505] "CP5710" "CP5710" "CP5711" "CP5714" "CP5720" "CP5734" "CP5739" "CP5740" "CP5754" "CP5756" "CP5757" "CP5766" [517] "CP5767" "CP5769" "CP5772" "CP5773" "CP5774" "CP5775" "CP5789" "CP5789" "CP5789" "CP5790" "CP5790" "CP5791" [529] "CP5791" "CP5791" "CP5792" "CP5801" "CP5823" "CP5824" "CP5825" "CP5853" "CP5879" "CP5893" "CP5911" "CP5922" [541] "CP5963" "CP5973" "CP5995" "CP6002" "CP6032" "CP6044" "CP6045" "CP6064" "CP6076" "CP6078" "CP6085" "CP6089" [553] "CP6095" "CP6148" "CP6167" "CP6184" "CP6197" "CP6204" "CP6230" "CP6234" "CP6236" "CP6243" "CP6247" "CP6257" [565] "CP6262" "CP6263" "CP6268" "CP6268" "CP6268" "CP6271" "CP6279" "CP6290" "CP6300" "CP6301" "CP6359" "CP6359" [577] "CP6360" "CP6390" "CP6401" "CP6410" "CP6429" "CP6436" "CP6452" "CP6466" "CP6466" "CP6466" "CP6469" "CP6472" [589] "CP6473" "CP6477" "CP6497" "CP6515" "CP6536" "CP6575" "CP6577" "CP6619" "CP6625" "CP6627" "CP6628" "CP6629" [601] "CP6635" "CP6636" "CP6648" "CP6696" "CP6704" "CP6705" "CP6714" "CP6750" "CP6764" "CP6785" "CP6811" "CP6812" [613] "CP6832" "CP6838" "CP6862" "CP6863" "CP6867" "CP6882" "CP6888" "CP6923" "CP6956" "CP6957" "CP6959" "CP7010" [625] "CP7011" "CP7011" "CP7011" "CP7012" "CP7030" "CP7044" "CP7045" "CP7053" "CP7128" "CP7130" "CP7132" "CP7134" [637] "CP7149" "CP7200" "CP7210" "CP7229" "CP7230" "CP7238" "CP7239" "CP7249" "CP7258" "CP7259" "CP7259" "CP7260" [649] "CP7261" "CP7269" "CP7270" "CP7270" "CP7271" "CP7272" "CP7281" "CP7282" "CP7282" "CP7283" "CP7284" "CP7293" [661] "CP7294" "CP7294" "CP7295" "CP7296" "CP7304" "CP7305" "CP7305" "CP7306" "CP7307" "CP7316" "CP7317" "CP7317" [673] "CP7318" "CP7320" "CP7361" "CP7362" "CP7363" "CP7363" "CP7364" "CP7375" "CP7413" "CP7414" "CP7415" "CP7440" [685] "CP7441" "CP7442" "CP7442" "CP7443" "CP7474" "CP7598" "CP7600" "CP7601" "CP7608" "CP7609" "CP7610" "CP7610" [697] "CP7611" "CP7613" "CP7615" "CP7616" "CP7617" "CP7619" "CP7620" "CP7621" "CP7621" "CP7622" "CP7625" "CP7628" [709] "CP7629" "CP7630" "CP7632" "CP7633" "CP7635" "CP7663" "CP7664" "CP7664" "CP7665" "CP7667" "CP7678" "CP7678" [721] "CP7678" "CP7678" "CP7679" "CP7679" "CP7679" "CP7679" "CP7679" "CP7680" "CP7682" "CP7682" "CP7744" "CP7745" [733] "CP7784" "CP7864" "CP7864" "CP7864" "CP7864" "CP7864" "CP7865" "CP7865" "CP7866" "CP7866" "CP7868" "CP7869" [745] "CP7870" "CP7871" "CP7872" "CP7873" "CP7873" "CP7874" "CP7877" "CP7884" "CP7889" "CP7893" "CP7908" "CP7962" [757] "CP7963" "CP7963" "CP7964" "CP7964" "CP7964" "CP7964" "CP7964" "CP7964" "CP7965" "CP7967" "CP7967" "CP7970" [769] "CP7972" "CP7973" "CP7974" "CP7991" "CP7991" "CP7991" "CP7995" "CP7997" "CP7997" "CP7997" "CP8005" "CP8007" [781] "CP8010" "CP8012" "CP8012" "CP8015" "CP8015" "CP8016" "CP8017" "CP8019" "CP8024" "CP8047" "CP8132" "CP8132" [793] "CP8133" "CP8136" "CP8138" "CP8141" "CP8142" "CP8142" "CP8142" "CP8574" "CP8579" "CP8591" "CP8595" "CP8598" [805] "CP8598" "CP8599" "CP8599" "CP8599" "CP8599" "CP8599" "CP8599" "CP8599" "CP8600" "CP8600" "CP8600" "CP8603" [817] "CP8604" "CP8606" "CP8614" "CP8615" "CP8617" "CP8617" "CP8618" "CP8619" "CP8620" "CP8620" "CP8621" "CP8622" [829] "CP8622" "CP8623" "CP8623" "CP8623" "CP8624" "CP8625" "CP8629" "CP8631" "CP8633" "CP8634" "CP8634" "CP8636" [841] "CP8638" "CP8639" "CP8640" "CP8641" "CP8644" "CP8644" "CP8645" "CP8646" "CP8646" "CP8648" "CP8651" "CP8652" [853] "CP8653" "CP8654" "CP8656" "CP8657" "CP8658" "CP8659" "CP8659" "CP8660" "CP8662" "CP8664" "CP8668" "CP8670" [865] "CP8671" "CP8672" "CP8674" "CP8675" "CP8675" "CP8677" "CP8679" "CP8681" "CP8681" "CP8688" "CP8689" "CP8690" [877] "CP8691" "CP8693" "CP8695" "CP8697" "CP8699" "CP8700" "CP8705" "CP8707" "CP8708" "CP8711" "CP8713" "CP8714" [889] "CP8715" "CP8716" "CP8719" "CP8720" "CP8721" "CP8722" "CP8723" "CP8724" "CP8725" "CP8727" "CP8728" "CP8747" [901] "CP8747" "CP8747" "CP8747" "CP8747" "CP8747" "CP8748" "CP8748" "CP8748" "CP8748" "CP8748" "CP8749" "CP8749" [913] "CP8749" "CP8749" "CP8749" "CP8749" "CP8750" "CP8750" "CP8750" "CP8752" "CP8753" "CP8754" "CP8754" "CP8755" [925] "CP8756" "CP8758" "CP8759" "CP8759" "CP8760" "CP8760" "CP8761" "CP8761" "CP8761" "CP8763" "CP8764" "CP8765" [937] "CP8767" "CP8768" "CP8769" "CP8774" "CP8774" "CP8776" "CP8777" "CP8779" "CP8780" "CP8780" "CP8781" "CP8781" [949] "CP8782" "CP8785" "CP8786" "CP8787" "CP8788" "CP8789" "CP8790" "CP8791" "CP8792" "CP8793" "CP8796" "CP8798" [961] "CP8802" "CP8803" "CP8805" "CP8807" "CP8808" "CP8812" "CP8814" "CP8816" "CP8819" "CP8821" "CP8822" "CP8824" [973] "CP8825" "CP8826" "CP8828" "CP8830" "CP8832" "CP8833" "CP8836" "CP8874" "CP8876" "CP8877" "CP8878" "CP8878" [985] "CP8878" "CP8878" "CP8878" "CP8878" "CP8879" "CP8879" "CP8879" "CP8879" "CP8881" "CP8881" "CP8882" "CP8883" [997] "CP8883" "CP8883" "CP8883" "CP8884" [ reached getOption("max.print") -- omitted 76 entries ] ``` ## Using the MS2 information to aid in the annotation of a chromatographic peak (pick 96.96004 for example): ```R $ ex_mz <- 96.96004 $ chromPeaks(dda_data, mz = ex_mz, ppm = 20) mz mzmin mzmax rt rtmin rtmax into intb maxo sn sample CP4972 96.96003 96.96001 96.96006 55.6840 49.69270 62.8274 25804864.0 25629857.3 3063722.5 267 1 CP4973 96.96006 96.96003 96.96008 12.1853 7.23388 18.3794 1749971.9 1600971.8 423904.2 36 1 CP4974 96.96006 96.96004 96.96008 22.7676 18.74580 25.9691 820956.5 722541.1 272789.7 23 1 CP4975 96.96002 96.96001 96.96006 65.5072 61.93030 68.7593 5307858.2 5213835.6 1094873.2 82 1 CP4976 96.96003 96.96001 96.96006 57.6777 57.67770 61.9303 8956539.4 8895549.4 2727754.0 267 1 ``` ## Extract MS2 spectra that were associated with the candidate chromatographic peak: ```R $ ex_spectra <- dda_spectra[dda_spectra$peak_id == "CP4972"] $ ex_spectra MSn data (Spectra) with 1 spectra in a MsBackendMzR backend: msLevel rtime scanIndex <integer> <numeric> <integer> F1.S00188 2 61.2675 188 ... 38 more variables/columns. file(s): new_cali_std_150.mzXML ``` ## MS2 spectrum created from all measured MS2 spectra for ions of chromatographic peak CP4972: ```R $ plotSpectra(ex_spectra) ``` ![](https://hackmd.io/_uploads/B1k_kNzq3.png) ```R for (i in 1:5440) { file_name <- paste0(output_folder, "/plot_", dda_spectra$peak_id[i], ".png") png(file_name, width = 864, height = 655) plotSpectra(dda_spectra[i]) dev.off() print(i) } ```