“…516 To identify the chemical constituents of essential oils, researchers often employ analytical tools such as FTIR, gas chromatography with flame ionization detection (GC-FID), GC and GC-MS. 518 In assessing the protective performances of essential oils, gravimetric and electrochemical methods such as WL, OCP, LPR, PDP and EIS are commonly utilized. 519 Using these techniques, the corrosion behaviour of a metallic specimen in the presence and absence of the essential oils is evaluated. For instance, using PDP and EIS methods, the inhibition performance of essential oils derived from the needles of black pine (Pinus nigra) was found to be 97% and 96%, respectively, at a concentration of 200 ppm.…”