Graph 1. Content range for organochlorine insecticides in mg/kg dry plant material
The contents of contaminants in some aromatic plant species from import were evaluated over a one-year period. The examined samples of plant drugs mostly contain residues of DDT in the range 0-0.00641 mg/kg and DDE 0-0.00421 mg/kg. The content of lindan is in the range 0-0.00823 mg/kg, and for the other HCH isomers (a+b+d) 0-0.00580 mg/kg. The concentration range for As is 0-1.00 mg/kg, whiles for Pb is 0-2.02 mg/kg. In four samples the content of Pb was more then 1.7 mg/kg. These findings supports the need for continues monitoring of aromatic plant contaminants.
Chemicals used in agriculture, because of their cumulative effects, are of potential risk for humans. The use of pesticides, artificial fertilisers, as well as the growing contamination of the environment, has enhanced the need for systematic control of toxic metals and persistent insecticides [1] .
Aromatic plants are used as remedies, spices, in cosmetic preparations, etc. For medicinal purposes they have been used, for example, as antiseptics and as corrective flavours for other drugs. Aromatic plants are mostly cultivated in tropic regions, especially in Asia [2] .
The aim of this research was to investigate the content of some organochlorine insecticides and toxic metals in some imported aromatic plants.
The investigated dry plant material was obtained from import samples with different geographic origin (Indonesia, India, China, Vietnam, etc.) in 1999. Entirely 63 samples of seven plant species were investigated: Allium sativum L. (n=10), Piper nigrum L. (black (n=25) and white (n=7)), Cinnamomum div. (n=9), Pimenta officinalis Berg. (n=4), Origano vulgare L. (n=3), Eugenia caryophyllata Thunb. (n=3), Zingiber officinale Rosc.(n=2).
DDT (dichlorodiphenyltrichloroethane), DDE (dichlorodiphenyldichloroethen) and isomers of HCH (hexachlorocyclohexan) (a-, b-, g- (lindan) and d-) were extracted and purified using the procedure described in an Hungarian National Standard [ 3] , and evaluated on the gas chromatograph Hewlett Packard 5890 Series II equipped with electron capture detector (ECD). Arsenic and lead were defined by atomic absorption spectrophotometry (AAS) after wet burning up by the AOAC procedure [4] , and determined on the Shimadzu AA-680 instrument (hydridetechnique) and PyeUnicam SP-192 (flame absorption technique), respectively. The results for all the contaminants are expressed in mg/kg of dry plant material. Detection limits for the insecticides were 0.00002 mg/kg, for arsenic 0.02 mg/kg and for lead 0.10 mg/kg.
Graph 1 shows the content range of the investigated organochlorine insecticides. The examined samples of plant drugs mostly contain residues of DDT and DDE. The highest concentration of 0.00641 mg/kg was determined for DDT in Cinnamomum div. In Piper nigrum (black) all six investigated insecticides were detected.
The use of DDT is restricted or prohibited in the majority of countries, which could be the reasons of the low concentrations found in the samples. Even so the results show that the aromatic plants were almost in every case contaminated with DDT and DDE, as the result of their accumulation and stability in the biosphere. Considering the stability, it's good solubility in lipids and the bioacumulation in the food chain; DDT represents a prototype of micropolutant of the environment.
Graph 2 shows the content range of arsenic and lead in the investigated samples. In all samples except in Piper nigrum (white) arsenic was detected. In tree samples the content of lead was more then 1.7 mg/kg, while the allowed top limit is 2.0 mg/kg [5], which indicate the enhanced pollution of the plants environment.
Presence of organochlorine insecticides is the result of their stability and bioacumulation in the environment, whereas the presence of lead indicate the pollution of the plants environment, which supports the need for continues monitoring of aromatic plant contaminants especially the content of lead.
Šovljanski R., Lazić S., Obradović S.(1990): Sadržaj teških metala i ostaci perzistentnih organohlorovanih insekticida u nekim industrijskim kulturama i lekovitom bilju, Čovek i životna sredina, 15, 1-2.
Jančić R., Stošić D., Mimica-Dukić N., Lakušić B. (1995): Aromaticne biljke Srbije, NIP Dečije Novine, Beograd-Gornji Milanovac.
Magyar Nepkoztarsasag, Orszagos Szabvany, Peszticidmaradekok vizsgalata elemis-zerekben, MSZ 14475/1-87, MSZ 14475/2-87.
Kenneth W. Boyer (Ed.) (1984): Metals and Other Elements at Trace Levels in Foods, In: Official Methods of Analysis, Centennial Edition, Assistant Business Manager Publications, Arlington, USA.
Pravilnik o količinama pesticida, metala i metaloida i drugih otrovnih supstanci, hemoterapeutika, anabolika i drugih supstancija koje se mogu nalaziti u namirnicama, Sl. list SRJ br.5/92.