Research results attained by Professor Saleh A. Aldosari and Dr. Mohamed H. El-Saeid of King Saud University in their study of Riyadh’s date fruit production have been published in a July issue of the Arabian Journal of Chemistry.
The study discussed four new techniques available in the monitoring of pesticide residues in the date fruit, a principal food in the Arab peninsula. In 2003, the World Health Organization acquired statistical date from 19 countries and estimated that world-wide 50,000 cases of poisoning were attributed to contaminated dates, with approximately 5,000 related deaths.
That year, 884,000 tons of dates were gathered from 21 million palm trees on the Arab Peninsula.
In their research, Dr. Aldosari, supervisor of the University's Red Palm Weevil Research Chair, and Dr. El-Saeid, associate professor of the university’s department of plant protection and the college of food and agricultural sciences, used date fruits acquired from eight Riyadh markets. The study focused on the extraction and analysis techniques of pesticides (hydrocarbon chlorinated, organophosphorus and pyrethroid) and residues of fungicides and herbicides in khalas, sukkari, nabout seif date fruit cultivars (and their seeds).
Using supercritical fluid extraction (SFE) and microwave solvent extraction (MSE), new and rapid techniques, the pesticide residue extraction process was conducted and analyzed. The analysis was performed without cleanup while using different detectors, revealed that the earlier method used was more sensitive, efficient and quick than traditional methods.
The recovery efficiency of SFE and MSE was 99 percent and 97 percent. The minimum detection limit (MDL) and repeatability achieved in this study met the standards set for tolerance-level monitoring of these pesticides. In fact, the results revealed the average level of pesticide residues such as acaricide, herbicides, and fungicides in the dates and seeds were less than the required maximum residue level.
Conversely, the residues of lindane, dieldrin, dimethoate, chlorpyrifos, and and all tested acaricide pesticide residues in date fruit samples exceeded maximum limites, citing the seriousness of date palm cultivation. In addition, results revealed a high concentration of pesticide acaricide in the date fruit seeds that on occasions are used for animal fodder. These results provided important information indicating the contamination of date fruits in Riyadh markets and demonstrated the need for appropriate measures required to curb this problem.
Dr. Aldosari believes a need exists for an awareness campaign, emphasizing to farmers the health hazards related to the excessive use of pesticides.