1D 1 H{ 35 Cl} double-echo (DE) RESPDOR NMR spectra were recorded with or without a Cl saturation pulse and a 50 kHz MAS frequency (Figures and). The application of Cl saturation pulse (tsat = 80 µs, nRF = 85 kHz) at an offset of 0 MHz from the reference Cl Larmor frequency caused significant 1 H signal dephasing, confirming the presence of Cl atoms in Si-NS. The 35 Cl-filtered 1 H NMR spectrum was acquired in ca. 10 min with only ca. 5 mg of sample, demonstrating that 1 H-detection enables the rapid detection of Cl within inorganic materials. This is not too surprising as all 1 H nuclei are effectively dipolar coupled to Cl since SiSi3Cl groups are homogenously distributed throughout the sample.