diff --git a/NAMESPACE b/NAMESPACE
index f61e1da..c44399c 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -9,6 +9,7 @@ export(MatchedSpectra)
 export(MatchedSummarizedExperiment)
 export(MzParam)
 export(MzRtParam)
+export(matchIonMode)
 export(matchMz)
 export(matchSpectra)
 export(matches)
@@ -43,6 +44,7 @@ importFrom(BiocParallel,bplapply)
 importFrom(BiocParallel,bpmapply)
 importFrom(MetaboCoreUtils,adductNames)
 importFrom(MetaboCoreUtils,mass2mz)
+importFrom(MetaboCoreUtils,mz2mass)
 importFrom(MsCoreUtils,ndotproduct)
 importFrom(MsCoreUtils,ppm)
 importFrom(MsCoreUtils,rbindFill)
diff --git a/R/matchIonMode.R b/R/matchIonMode.R
new file mode 100644
index 0000000..d733d25
--- /dev/null
+++ b/R/matchIonMode.R
@@ -0,0 +1,137 @@
+#' @noRd
+setClass("IonModeParam",
+         slots = c(
+           tolerance = "numeric",
+           ppm = "numeric",
+           queryAdducts = "adductClass",
+           targetAdducts = "adductClass"),
+         contains = "Param",
+         prototype = prototype(
+           tolerance = 0,
+           ppm = 5,
+           queryAdducts = "[M+H]+",
+           targetAdducts = "[M-H]-"),
+         validity = function(object) {
+           msg <- NULL
+           if (length(object@tolerance) != 1 || object@tolerance < 0) {
+             msg <- c("'tolerance' has to be a positive number of length 1")
+           }
+
+           if (length(object@ppm) != 1 || object@ppm < 0) {
+             msg <- c("'ppm' has to be a positive number of length 1")
+           }
+
+           if (is(object@queryAdducts, "data.frame")) {
+             if(any(!c("mass_add", "mass_multi") %in% colnames(object@adducts)))
+               msg <- paste0("Columns \"mass_add\" and \"mass_multi\" must be ",
+                             "present when adducts is a data.frame")
+           } else {
+             if (!all(object@queryAdducts %in% c(adductNames("positive"),
+                                            adductNames("negative"))))
+               msg <- paste0("Unknown adducts, please check MetaboCoreUtils",
+                             " for valid adducts")
+           }
+
+           if (is(object@targetAdducts, "data.frame")) {
+             if(any(!c("mass_add", "mass_multi") %in% colnames(object@adducts)))
+               msg <- paste0("Columns \"mass_add\" and \"mass_multi\" must be ",
+                             "present when adducts is a data.frame")
+           } else {
+             if (!all(object@targetAdducts %in% c(adductNames("positive"),
+                                                 adductNames("negative"))))
+               msg <- paste0("Unknown adducts, please check MetaboCoreUtils",
+                             " for valid adducts")
+           }
+
+           msg
+
+         })
+
+#' @title m/z matching
+#'
+#' @name matchIonMode
+#'
+#' @description
+#'
+#' The `matchIonMode` function is a prototype.
+NULL
+
+#' @rdname matchIonMode
+#'
+#' @export
+setGeneric("matchIonMode", function(query, target, param, ...)
+  standardGeneric("matchIonMode"))
+
+#' @rdname matchIonMode
+#'
+#' @importFrom BiocParallel bpmapply SerialParam
+setMethod("matchIonMode",
+          signature = c(query = "numeric",
+                        target = "numeric",
+                        param = "IonModeParam"),
+          function(query, target, param, BPPARAM = SerialParam()) {
+
+            query_mass <- .mz_to_mass_df(query, param@queryAdducts)
+            target_mass<- .mz_to_mass_df(target, param@targetAdducts)
+
+            queryl <- nrow(query_mass)
+
+            matches <- vector("list", queryl)
+
+            for(i in seq_len(queryl)) {
+
+              matches[[i]] <- .getMassMatches(query_mass$index[i],
+                                              query_mass$mass[i],
+                                              query_mass$adduct[i],
+                                              target = target_mass,
+                                              tolerance = param@tolerance,
+                                              ppm = param@ppm)
+
+            }
+
+            Matched(query = query, target = target,
+                    matches = do.call(rbind, matches),
+                    metadata = list(param = param))
+
+          })
+
+#' @author Michael Witting
+#'
+#' @param queryIndex `integer(1)` with the index of the query.
+#'
+#' @param queryMass `numeric(1)` with the mass of the query.
+#'
+#' @param target `data.frame` with columns `"index"`, `"mass"` and  `"adduct"`.
+#'
+#' @noRd
+.getMassMatches <- function(queryIndex, queryMass, queryAdduct, target, tolerance, ppm) {
+
+  diffs <- abs(queryMass - target$mass)
+  cls <- which(diffs <= (tolerance + ppm(queryMass, ppm)))
+
+  if (length(cls)) {
+    data.frame(query_idx = queryIndex,
+               target_idx = target$index[cls],
+               adduct = paste0(queryAdduct, " / ", target$adduct[cls]),
+               score = diffs[cls])
+  } else {
+    data.frame(query_idx = integer(),
+               target_idx = integer(),
+               adduct = character(),
+               score = numeric())
+  }
+}
+
+#' creates a `data.frame` with columns `"index"`, `"adduct"` and `"mz"` from
+#' provided mass values `x` and adduct definition `adducts`. `"index"` is the
+#' index of the mass in the input vector `x`.
+#'
+#' @importFrom MetaboCoreUtils mz2mass
+#'
+#' @noRd
+.mz_to_mass_df <- function(x, adducts) {
+  mass <- mz2mass(x, adducts)
+  data.frame(index = rep(seq_along(x), .nelements(adducts)),
+             adduct = rep(colnames(mass), each = length(x)),
+             mass = as.numeric(mass))
+}
diff --git a/man/matchIonMode.Rd b/man/matchIonMode.Rd
new file mode 100644
index 0000000..57c51f4
--- /dev/null
+++ b/man/matchIonMode.Rd
@@ -0,0 +1,14 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/matchIonMode.R
+\name{matchIonMode}
+\alias{matchIonMode}
+\alias{matchIonMode,numeric,numeric,IonModeParam-method}
+\title{m/z matching}
+\usage{
+matchIonMode(query, target, param, ...)
+
+\S4method{matchIonMode}{numeric,numeric,IonModeParam}(query, target, param, BPPARAM = SerialParam())
+}
+\description{
+The \code{matchIonMode} function is a prototype.
+}