The chemical constituents of leaf and peel essential oil of Citrus medica L. were analysed by gas chromatography mass spectroscopy (GC-MS). Nineteen components accounting for 99.9% of the oil were identified in leaf oil. The major constituents are erucylamide (28.43%), limonene (18.36%) and citral (12.95%). The peel oil contains forty three components accounting for 99.8% of the total oil and the major components are isolimonene (39.37%), citral (23.12%) and limonene (21.78%).

A thin layer chromatographic method has been developed that distinguishes and differentiates true cardamom (Elletaria cardamomum Maton) and greater cardamom (Amomum subulatum Roxb). Extracted volatile oils are chromatographed on silica gel G with n-hexanediethyl ether (80+20) solvent system and visualized with a saturated solution of antimony trichloride in chloroform. The chromatographic pattern permits the detection of adulteration of one by the other at levels as low as 5%.

A rapid thin layer chromatographic method has been developed to detect Carum bulbocastanum Koch in Carum carvi Linn. The volatile essential oils are developed on silica gel G plates, using benzene-petroleum ether and visualized by 2,4-dinitrophenylhydrazine spray. This procedure can also differentiate mixtures of the 2 seeds.