# Real Time Annotation

#### 2020-10-11

#### Package

peakPantheR 1.4.0

Package: peakPantheR
Authors: Arnaud Wolfer

# 1 Introduction

The `peakPantheR` package is designed for the detection, integration and reporting of pre-defined features in MS files (e.g. compounds, fragments, adducts, …).

The Real Time Annotation is set to detect and integrate multiple compounds in one file at a time. It therefore can be deployed on a LC-MS instrument to integrate a set of pre-defined features (e.g. spiked standards) as soon as the acquisition of a sample is completed.

Using the faahKO raw MS dataset as an example, this vignette will:

- Detail the Real Time Annotation concept
- Apply the Real Time Annotation to a subset of pre-defined features in the faahKO dataset

## 1.1 Abbreviations

- ROI: Regions Of Interest
  - reference RT / m/z windows in which to search for a feature
- uROI: updated Regions Of Interest
  - modifed ROI adapted to the current dataset which override the reference ROI
- FIR: Fallback Integration Regions
  - RT / m/z window to integrate if no peak is found
- TIC: Total Ion Chromatogram
  - the intensities summed across all masses for each scan
- EIC: Extracted Ion Chromatogram
  - the intensities summed over a mass range, for each scan

# 2 Real Time Annotation Concept

Real time compound integration is set to process multiple compounds in one file at a time.

To achieve this, `peakPantheR` will:

- load a list of expected RT / m/z regions of interest (ROI)
- detect features in each ROI and keep the highest intensity one
- determine peak statistics for each feature
- return:
  - TIC
  - a table with all detected compounds for that file (row: compound, col: statistic)
  - EIC for each ROI
  - sample acquisition date-time from the mzML metadata (if available)
  - save EIC plots to disk

# 3 Real Time Annotation Example

In the following example we will target two pre-defined features in a single raw MS spectra file from the faahKO package. For more details on the installation and input data employed, please consult the Getting Started with peakPantheR vignette.

## 3.1 Input Data

The path to a MS file from the faahKO is located and used as input spectra:

    library(faahKO)
    ## file paths
    input_spectraPath  <- c(system.file('cdf/KO/ko15.CDF', package = "faahKO"))
    input_spectraPath
    #> [1] "C:/Users/biocbuild/bbs-3.12-bioc/R/library/faahKO/cdf/KO/ko15.CDF"

Two targeted features (e.g. compounds, fragments, adducts, …) are defined and stored in a table with as columns:

- `cpdID` (numeric)
- `cpdName` (character)
- `rtMin` (sec)
- `rtMax` (sec)
- `rt` (sec, optional / `NA`)
- `mzMin` (m/z)
- `mzMax` (m/z)
- `mz` (m/z, optional / `NA`)

    # targetFeatTable
    input_targetFeatTable <- data.frame(matrix(vector(), 2, 8, dimnames=list(c(),
                            c("cpdID", "cpdName", "rtMin", "rt", "rtMax", "mzMin",
                            "mz", "mzMax"))), stringsAsFactors=FALSE)
    input_targetFeatTable[1,] <- c("ID-1", "Cpd 1", 3310., 3344.888, 3390.,
                                    522.194778, 522.2, 522.205222)
    input_targetFeatTable[2,] <- c("ID-2", "Cpd 2", 3280., 3385.577, 3440.,
                                    496.195038, 496.2, 496.204962)
    input_targetFeatTable[,c(3:8)] <- sapply(input_targetFeatTable[,c(3:8)],
                                                as.numeric)

cpdID | cpdName | rtMin | rt | rtMax | mzMin | mz | mzMax
--- | --- | --- | --- | --- | --- | --- | ---
ID-1 | Cpd 1 | 3310 | 3344.888 | 3390 | 522.194778 | 522.2 | 522.205222
ID-2 | Cpd 2 | 3280 | 3385.577 | 3440 | 496.195038 | 496.2 | 496.204962

## 3.2 Run Single File Annotation

`peakPantheR_singleFileSearch()` takes as input a `singleSpectraDataPath` pointing to the file to process and `targetFeatTable` defining the features to integrate. The resulting annotation contains all the fitting and integration properties:

    library(peakPantheR)
    annotation <- peakPantheR_singleFileSearch(
                                        singleSpectraDataPath = input_spectraPath,
                                        targetFeatTable = input_targetFeatTable,
                                        peakStatistic = TRUE,
                                        curveModel = 'skewedGaussian',
                                        verbose = TRUE)
    #> Polarity can not be extracted from netCDF files, please set manually the polarity with the 'polarity' method.
    #> Reading data from 2 windows
    #> Data read in: 2.44 secs
    #> Warning: rtMin/rtMax outside of ROI; datapoints cannot be used for mzMin/mzMax calculation, approximate mz and returning ROI$mzMin and ROI$mzMax for ROI #1
    #> Found 2/2 features in 0.03 secs
    #> Peak statistics done in: 0 secs
    #> Feature search done in: 3.23 secs

    annotation$TIC
    #> [1] 2410533091

    ## acquisition time cannot be extracted from NetCDF files
    annotation$acquTime
    #> [1] NA

    annotation$peakTable

Table continues below
found | rtMin | rt | rtMax | mzMin | mz | mzMax
--- | --- | --- | --- | --- | --- | ---
TRUE | 3309.759 | 3346.828 | 3385.41 | 522.1948 | 522.2 | 522.2052
TRUE | 3345.377 | 3386.529 | 3428.279 | 496.2 | 496.2 | 496.2

Table continues below
peakArea | maxIntMeasured | maxIntPredicted | cpdID | cpdName | is_filled
--- | --- | --- | --- | --- | ---
26133727 | 889280 | 901015.8 | ID-1 | Cpd 1 | FALSE
35472141 | 1128960 | 1113577 | ID-2 | Cpd 2 | FALSE

ppm_error | rt_dev_sec | tailingFactor | asymmetryFactor
--- | --- | --- | ---
0.02337616 | 1.939759 | 1.015357 | 1.026824
0.02460103 | 0.9518072 | 1.005378 | 1.009318

    annotation$curveFit
    #> [[1]]
    #> $amplitude
    #> [1] 162404.8
    #>
    #> $center
    #> [1] 3341.888
    #>
    #> $sigma
    #> [1] 0.07878613
    #>
    #> $gamma
    #> [1] 0.00183361
    #>
    #> $fitStatus
    #> [1] 2
    #>
    #> $curveModel
    #> [1] "skewedGaussian"
    #>
    #> attr(,"class")
    #> [1] "peakPantheR_curveFit"
    #>
    #> [[2]]
    #> $amplitude
    #> [1] 199249.1
    #>
    #> $center
    #> [1] 3382.577
    #>
    #> $sigma
    #> [1] 0.07490442
    #>
    #> $gamma
    #> [1] 0.00114719
    #>
    #> $fitStatus
    #> [1] 2
    #>
    #> $curveModel
    #> [1] "skewedGaussian"
    #>
    #> attr(,"class")
    #> [1] "peakPantheR_curveFit"

    annotation$ROIsDataPoint
    #> [[1]]
    #>          rt    mz    int
    #> 1  3315.154 522.2   2187
    #> 2  3316.719 522.2   3534
    #> 3  3318.284 522.2   6338
    #> 4  3319.849 522.2  11718
    #> 5  3321.414 522.2  21744
    #> 6  3322.979 522.2  37872
    #> 7  3324.544 522.2  62424
    #> 8  3326.109 522.2  98408
    #> 9  3327.673 522.2 152896
    #> 10 3329.238 522.2 225984
    #> 11 3330.803 522.2 308672
    #> 12 3332.368 522.2 399360
    #> 13 3333.933 522.2 504000
    #> 14 3335.498 522.2 614656
    #> 15 3337.063 522.2 711872
    #> 16 3338.628 522.2 784704
    #> 17 3340.193 522.2 836608
    #> 18 3341.758 522.2 866304
    #> 19 3343.323 522.2 882304
    #> 20 3344.888 522.2 889280
    #> 21 3346.453 522.2 888256
    #> 22 3348.018 522.2 866816
    #> 23 3349.583 522.2 827392
    #> 24 3351.148 522.2 777728
    #> 25 3352.713 522.2 727040
    #> 26 3354.278 522.2 678464
    #> 27 3355.843 522.2 629120
    #> 28 3357.408 522.2 578048
    #> 29 3358.973 522.2 524288
    #> 30 3360.538 522.2 471040
    #> 31 3362.102 522.2 416320
    #> 32 3363.667 522.2 360064
    #> 33 3365.232 522.2 302400
    #> 34 3366.797 522.2 249152
    #> 35 3368.362 522.2 202560
    #> 36 3369.927 522.2 161024
    #> 37 3371.492 522.2 123520
    #> 38 3373.057 522.2  93160
    #> 39 3374.622 522.2  71856
    #> 40 3376.187 522.2  58392
    #> 41 3377.752 522.2  51072
    #> 42 3379.317 522.2  48376
    #> 43 3380.882 522.2  49168
    #> 44 3382.447 522.2  53120
    #> 45 3384.012 522.2  62488
    #> 46 3385.577 522.2  78680
    #> 47 3387.142 522.2 102840
    #> 48 3388.707 522.2 134656
    #>
    #> [[2]]
    #>          rt    mz     int
    #> 1  3280.725 496.2    1349
    #> 2  3290.115 496.2    2069
    #> 3  3291.680 496.2    3103
    #> 4  3293.245 496.2    5570
    #> 5  3294.809 496.2   10730
    #> 6  3296.374 496.2   20904
    #> 7  3297.939 496.2   38712
    #> 8  3299.504 496.2   64368
    #> 9  3301.069 496.2   97096
    #> 10 3302.634 496.2  136320
    #> 11 3304.199 496.2  182080
    #> 12 3305.764 496.2  233472
    #> 13 3307.329 496.2  288064
    #> 14 3308.894 496.2  341248
    #> 15 3310.459 496.2  386560
    #> 16 3312.024 496.2  419648
    #> 17 3313.589 496.2  441344
    #> 18 3315.154 496.2  454592
    #> 19 3316.719 496.2  459776
    #> 20 3318.284 496.2  456320
    #> 21 3319.849 496.2  444736
    #> 22 3321.414 496.2  425408
    #> 23 3322.979 496.2  397888
    #> 24 3324.544 496.2  365952
    #> 25 3326.109 496.2  329856
    #> 26 3327.673 496.2  288832
    #> 27 3329.238 496.2  244864
    #> 28 3330.803 496.2  207616
    #> 29 3332.368 496.2  177216
    #> 30 3333.933 496.2  148544
    #> 31 3335.498 496.2  119240
    #> 32 3337.063 496.2   94736
    #> 33 3338.628 496.2   76832
    #> 34 3340.193 496.2   64048
    #> 35 3341.758 496.2   53744
    #> 36 3343.323 496.2   45704
    #> 37 3344.888 496.2   39576
    #> 38 3346.453 496.2   35080
    #> 39 3348.018 496.2   31432
    #> 40 3349.583 496.2   28904
    #> 41 3351.148 496.2   27064
    #> 42 3352.713 496.2   25632
    #> 43 3354.278 496.2   24480
    #> 44 3355.843 496.2   23840
    #> 45 3357.408 496.2   23688
    #> 46 3358.973 496.2   24680
    #> 47 3360.538 496.2   28608
    #> 48 3362.102 496.2   39616
    #> 49 3363.667 496.2   63344
    #> 50 3365.232 496.2  107352
    #> 51 3366.797 496.2  182144
    #> 52 3368.362 496.2  295232
    #> 53 3369.927 496.2  438016
    #> 54 3371.492 496.2  592256
    #> 55 3373.057 496.2  737408
    #> 56 3374.622 496.2  858624
    #> 57 3376.187 496.2  938368
    #> 58 3377.752 496.2  982976
    #> 59 3379.317 496.2 1015232
    #> 60 3380.882 496.2 1057280
    #> 61 3382.447 496.2 1095680
    #> 62 3384.012 496.2 1122304
    #> 63 3385.577 496.2 1128960
    #> 64 3387.142 496.2 1111040
    #> 65 3388.707 496.2 1058816
    #> 66 3390.272 496.2  996608
    #> 67 3391.837 496.2  942272
    #> 68 3393.402 496.2  888640
    #> 69 3394.966 496.2  820160
    #> 70 3396.531 496.2  744448
    #> 71 3398.096 496.2  674688
    #> 72 3399.661 496.2  609600
    #> 73 3401.226 496.2  543552
    #> 74 3402.791 496.2  480896
    #> 75 3404.356 496.2  428032
    #> 76 3405.921 496.2  387520
    #> 77 3407.486 496.2  350976
    #> 78 3409.051 496.2  313984
    #> 79 3410.616 496.2  276224
    #> 80 3412.181 496.2  243776
    #> 81 3413.746 496.2  219264
    #> 82 3415.311 496.2  202368
    #> 83 3416.876 496.2  189184
    #> 84 3418.441 496.2  174272
    #> 85 3420.006 496.2  158080
    #> 86 3421.571 496.2  143744
    #> 87 3423.136 496.2  135808
    #> 88 3424.701 496.2  131648
    #> 89 3426.266 496.2  126784
    #> 90 3427.831 496.2  118328
    #> 91 3429.395 496.2  109144
    #> 92 3430.960 496.2  101944
    #> 93 3432.525 496.2   96896
    #> 94 3434.090 496.2   92048
    #> 95 3435.655 496.2   86408
    #> 96 3437.220 496.2   81288
    #> 97 3438.785 496.2   78144

`peakPantheR_singleFileSearch()` takes multiple parameters that can alter the file annotation:

- `peakStatistic` if `TRUE` calculates additional peak statistics: ‘ppm_error’, ‘rt_dev_sec’, ‘tailing factor’ and ‘asymmetry factor’
- `plotEICsPath` if not `NA` will save a `.png` of all ROI EICs at the path provided (expects `'filepath/filename.png'` for example). If `NA` no plot is saved
- `getAcquTime` if `TRUE` the sample acquisition date-time is extracted from the `mzML` metadata. Acquisition time cannot be extracted from other file formats. The additional file access will impact run time
- `FIR` if not `NULL`, defines the Fallback Integration Regions (FIR) to integrate when a feature is not found.
- `curveModel`, defines the peak-shape model to fit to each EIC. By default, a ‘skewedGaussian’ model is used. The other alternative is the exponentially modified gaussian ‘emgGaussian’ model.
- `verbose` if `TRUE` messages calculation progress, time taken and number of features found (total and matched to targets)
- `...` passes arguments to `findTargetFeatures` to alter peak-picking parameters (e.g. the curveModel, the sampling or fitting parameters)

The summary plot generated by `plotEICsPath`, corresponding to the EICs of each integrated regions of interest is as follow:

> EICs plot: Each panel correspond to a targeted feature, with the EIC extracted on the `mzMin`, `mzMax` range found. The red dot marks the RT peak apex, and the red line highlights the RT peakwidth range found (`rtMin`, `rtMax`)

# 4 See Also

- Getting Started with peakPantheR
- Parallel Annotation
- Graphical user interface use