Microcystin-LR in surface water of Ponjavica river ; Mikrocistin-LR u površinskim vodama reke Ponjavice
Background/Aim. Cyanobacterial toxins befall a group of various compounds according to chemical structure and health effects on people and animals. The most significant in this large group of compounds are microcystins. Their presence in water used for human consumption causes serious health problems, liver beeing the target organ. Microcystins are spread all over the world. Waterblooms of cyanobacterias and their cyanotoxins are also common in the majority of surface waters in Serbia. The aim of this study was to propose HPLC method for determination of mikrocystin-LR, to validate the method and to use it for determination of microcystin-LR in the surface water of the river Ponjavica. The Ponjavica is very eutrophic water and has ideal conditions for the cyanobacterial growth. Methods. Sample of water form the Ponjavica river were collected during the summer 2008. Coupled columns (HLB, Sep-Pak), were used for sample preparation and HPLC/PDA method was used for quantification of microcystin- LR. Results. Parameters of validation show that the proposed method is simple, fast, sensitive (0.1 mg/L) and selective with the yield of 89%-92%. The measuring uncertainty of 5% was obtained. The obtained results for surface water show that microcystin concentration reached the maximum level during August and September (1.5 μg/L). The value is higher than maximum allowable concentration of microcystin in drinking water (1 μg/L) proposed by WHO. Conclusion. This study contributes to the issue of pollution of the National Park Ponjavica. Besides, literature data and WHO clearly point out harmfulness of cyanobasterias and their toxins and implicate the necessity of legislation concerning determination and monitoring of these toxins in our country. Method used for quentification of mycrocystin-LR was shown to be sensitive, selective, rapid and simple and could be recommended for routine determination of this toxin. ; Uvod/Cilj. Cijanotoksini, odnosno toksini cijanobakterija, spadaju u grupu raznovrsnih jedinjenja kako po hemijskoj strukturi, tako i po dejstvu na ljude i životinje. Najveći značaj u ovoj velikoj grupi jedinjenja imaju mikrocistini. Njihovo prisustvo u vodi može da izazove toksične efekte, posebno na jetru. Mikrocistini su rasprostranjeni širom sveta. Cvetanje toksičnih cijanobakterija i njihovi cijanotoksini karakteristični su i za neke površinske vode u Srbiji. Cilj ovog rada bio je da se uvede HPLC metoda za određivanje mikrocistina-LR, da se izvrši validacija metode i odredi sadržaj mikrocistina-LR u površinskoj vodi reke Ponjavice, veoma eutrofne reke, koja poseduje idealne uslove za razvoj cijanobakterija. Metode. Za pripremu uzoraka korišćeni su HLB i C8 ulošci, a za dodatno prečišćavanje upotrebljeni su Sep-Pak silika ulošci. Kvantifikacija mikrocistina-LR vršena je metodom HPLC pomoću detektora na principu fotodiode (HPLC/PDA) korišćenjem kolone RP C18 Zorbax Eclips (4,6x150,5 μm), upotrebom mobilne faze sastava 0,1% rastvor trifluorosirćetne kiseline (TFA) u metanolu: 0,1% vodeni rastvor TFA u odnosu 60 : 40 (v/v), na 238 nm. Retenciono vreme mikrocistina-LR iznosilo je 10 min. Uzorci vode reke Ponjavice za analizu mikrocistina-LR sakupljeni su tokom perioda jun-novembar 2008. godine. Rezultati. Validacijom metode utvrđena je osetljivost 0,1 μg/L, prinos 89-92% i merna nesigurnost od ± 5%. Rezultati uzoraka vode reke Ponjavice pokazali su da je vrednost mikrocistina-LR dostigla maksimum tokom avgusta i septembra (1,5 μg/L), i da je iznad maksimalno dozvoljene koncentracije za pijaću vodu (1 μg/L) prema preporuci Svetske zdravstvene organizacije. Zaključak. Parametri validacije pokazuju da je predložena metoda osetljiva i selektivna, što je, uz činjenicu da je jednostavna i brza, čini pogodnom za rutinsko određivanje mikrocistina-LR. Predloženom metodom određene su povišene koncentracije ovog toksina cijanobakterija u uzorcima vode reke Ponjavice, koje ukazuju na zagađenost Parka prirode 'Ponjavica'.