Elemental analysis of Ginkgo biloba leaf samples collected during one vegetation period.

The object of our work was the identification and quantification of inorganic elements in Ginkgo biloba L. leaves (Ginkgonis folium, Ginkgoaceae) by X-ray fluorescence analysis. The plant material was obtained from a 50-years-old female tree at the Comenius University Botanical Garden (Bratislava, Slovakia). Leaves were collected from early May to late September, with the last sample consisting of fallen leaves. The elements analyzed were: phosphorus, sulfur, potassium, calcium, scandium, iron, zinc, yttrium, molybdenum, tellurium, samarium, gadolinium, dysprosium, iridium, thallium and lead. The amounts of the monitored heavy metals were below the limits specified in Ph. Eur. 7 and PhS 1.

The influence of the harvest cut height on the quality of the herbal drugs Melissae folium and Melissae herba.

Variability in both the content and quality of essential oil was observed in herb and leaf drugs in dependence on the harvest cut height of lemon balm (Melissa officinalis L. cv. Citra). Three different cuts were carried out on the respective plants. The oil content in the herb was highest in the top third (0.13 % V/m), satisfactory in the herb including both the top and middle thirds (0.08 % V/m) and lowest in the whole herb (0.06 % V/m). The oil content in the leaves of the respective herbs was in the range 0.39 % - 0.14 % V/m (top third part - whole aerial part). The percentage of citrals, linalool and beta-caryophyllene in essential oil decreased in the basipetal direction, whilst the amounts of beta-caryophyllene oxide and citronellal increased in the same direction. Citrals (A and B): 55.79 % in the top third part of the herb, 48.46 % in the whole herb, 59.74 % and 56.87 % in the leaves from that parts, respectively. Similarly, beta-caryophyllene: 5.01 %, 3.87 %, 6.97 %, 5.13 %; beta-caryophyllene oxide: 17.19 %, 24.07 %, 15.64 %, 17.82 %; citronellal: 2.73 %, 5.51 %, 2.82 %, 6.44 %.