One-tube experiments

In addition, slow exchange of the isotopes is also a requirement to observe resonances due to both species. This is usually not a problem for heavy isotopes such as and so on or for D and T attached to nonelectronegative elements 

---

Isotope eHects on chemical shifts must preferably be measured in a one-tube experiment, meaning that both isotopic species should be present in the same tube. This leads to the spectra shown in Figure 6.4 with resonances due to both isotopes. 

---