For example, the Scientific Working Groups for the Identification of Seized Drugs (SWG-DRUG) and Fire and Explosions (SWGFEX) both categorize techniques broadly into those providing presumptive, indicative and confirmatory evidence. The SWGFEX guidelines for post-blast explosive identification are particularly relevant example for trace chemical NTA (recommended guidelines for the forensic identification of post-blast explosive residues). An array of confirmatory techniques are categorized by their ability to offer structural or elemental level detail and include Raman, FTIR, X-Ray Diffraction, in addition to LC-MS and GC-MS. Energetic materials are well known to be very challenging to measure by any single method or technique. Gaps in the measurable space that exist for methods that use confirmatory techniques are fundamentally considered. This is especially true for chromatography coupled to mass spectrometry. Given the potential undesirable outcomes of a 'false negative' in this particular field, the combination of techniques is critical (e.g., to identify both inorganic and organic explosives). Even when using MS, the choice of ionization technique in LC-MS is also extremely important (e.g., ESI is normally more suitable for nitrate esters, APCI is better for nitrotoluenes, and neither are particularly effective for detection of some explosives like nitroglycerin or hexamethylene triperoxide diamine 142 ). For the identification of intact/bulk drugs, SWGDRUG also consider NMR spectroscopy a confirmatory technique (Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG) Recommendations, 2019). With regards to exposomics, NMR has been used for many years for the identification of biomolecules in exposome research [REF- NMR Wishart]. Though less sensitive than MS generally, higher field instruments, multiple scans, different probes, or hyperpolarisation used together with sample pre-concentration methods may improve its contribution for identification of new substances at trace concentrations in complex samples. As for the measured exposome chemical space, the main challenges are the raw data quality assessment, incomplete pre-processing workflows, and identification workflows. The data quality assessment must become independent from the data pre-processing workflows as they may be a major source of error into final results, for example low quality MS/MS spectrum due to the lack of deconvolution algorithms. The current NTA workflows are set to focus of a single sample or batch of samples analyzed with one specific method. This limitation hinders large scale retrospective analysis of archive data as most of the signals may remain unidentified. Moreover, the use of the same set of internal standards may not be adequate. Therefore, the development of alignment algorithms that are based on the raw data or the raw feature lists is must for being able to fully take advantage of the publicly available archived data. Finally, when it comes to identification, the current approaches are based on a set number of matched fragments and hard set thresholds. This may not be the most adequate way forward as different chemicals may need different parameters for their high confidence identification. For example, for PFAS chemicals having two or three fragments may be enough while for hormone like chemicals sometimes even 100 fragments are not enough. Moreover, depending on the levels of background signal and matrix effects, the mass accuracy of the instrument may be different, resulting in better match with incorrect candidates.