Collection was modified; enumeration operation might not execute. datatable c#
using CentroidsList = System.Collection.Generic.List<...>; //put the type of the element of newSpectrum.PeakCentroids
//...
CentroidsList list = new CentroidsList();
foreach (var element in newSpectrum.PeakCentroids)
if (SomeCondition(element))
list.Add(element);
foreach (var element in list)
newSpectrum.PeakCentroids.Remove(element);