The paradigm for missing cluster and missing linker defect research is UiO-66, a MOF consisting of Zr6O4(OH)4 clusters bridged by terephthalate (1,4-benzodicarboxylic acid or bdc) linkers. Liu et al. impressively wielded a low-dose high-resolution transmission electron microscopy approach to show the nature of its missing cluster and linker defects at a sub-unit cell resolution. To quantify the amount of missing linkers on a bulk scale, TGA is currently considered the gold standard, with the most common processing method presented by Shearer et al., who measured the thermogram under air, thus allowing for combustion, which should result in a residue of only ZrO2 at high temperature. They then renormalize the thermogram to this final plateau and calculate the difference between the theoretical mass of the MOF and the observed mass. However, accurately determining the mass of the linkers from the thermogram is not always straightforward. Valenzano et al. used TGA coupled with mass spectrometry (TGA-MS) to pinpoint the temperature range where the physisorbed water and residual solvent are lost but the linkers are still intact and they found this range to be between 300 and 500 °C. Sannes et al., who worried about incomplete removal of e.g. monobenzoate modulators in this range, recently proposed to incorporate an isothermal plateau at 200 °C in the thermogram instead, assuming that the physisorbed water is removed at this temperature and they identified capping agents and charge balancing (H2O/OH -) ions in their stoichiometry using NMR spectroscopy and mass and charge balance equations. A very instructive overview of the literature on TGA on MOFs is given by Abánades Lázaro, who also presented equations for many different use cases. Several concerns can be expressed when using solely TGA for linker quantification: one assumes that the residue is pure metal oxide, the origin of the oxygen is not always clear (from air or ligand?), one needs to know the identity of the ligands and the defects and missing clusters cannot be differentiated. However, a good correlation of TGA mass losses with the Brunauer-Emmett-Teller (BET) analysis of N2-adsorption isotherms, powder X-ray diffraction, catalytic activity, modulator concentration and relative linker concentration in MTV-MOFs 29 has been reported.