A waveform analytical device 4 which analyzes a target waveform which is a chromatogram or an optical spectrum includes a waveform division unit 54 configured to divide the target waveform into a plurality of partial waveforms, a determination unit 55 configured to determine whether each of the plurality of partial waveforms of the target waveform is a peak portion using a learned model created by machine learning using a plurality of sets of a plurality of partial waveforms created by dividing a reference waveform having a peak portion whose position is known, and a classification unit 56 configured to classify the target waveform into a peak region where the peak portion continues and a non-peak region other than the peak region based on a determination result from the determination unit.

A method of acquiring mass spectrum peak data of fragment ions from mass spectra for fragment ions generated in an LC-MS/MS measuring instrument may include acquiring a molecular structure of the fragment ions and fragment ion graph data by using the acquired data, and deriving a candidate molecular structure of a target substance by assembling fragment ion graphs.

Systems/techniques are provided for facilitating inconclusive-triggered reinjection for mass spectrometry screening. In various embodiments, a system can access a screening list specifying a plurality of target chemical compounds. In various aspects, the system can classify respective ones of the plurality of target chemical compounds as being present or absent in a sample, based on causing a chromatograph and mass spectrometer to perform on the sample an iterative injection protocol whose subsequent iterations are progressively compound-selective and triggered by inconclusive presence or absence classifications from prior iterations.