Detection of Nitrogen and Sulphur Together

If both $$\text{N}$$ and $$\text{S}$$ are present, fusion produces Sodium Thiocyanate ($$\text{NaSCN}$$):

$$\text{Na} + \text{C} + \text{N} + \text{S} \xrightarrow{\Delta} \text{NaSCN}$$

Adding $$\text{Fe}^{3+}$$ gives a Blood-Red coloration due to ferric thiocyanate:

$$\text{Fe}^{3+} + \text{SCN}^- \to [\text{Fe(SCN)}]^{2+} \text{ (Blood Red)}$$

(Note: No Prussian blue is formed unless excess sodium is used to decompose $$\text{NaSCN}$$ into $$\text{NaCN}$$ and $$\text{Na}_2\text{S}$$).