Extraction of organic pollutants from soil by soil solid-phase dispersion

Abstract

U ovom radu razvijena je metoda ekstrakcije organskih zagađivala, policikličkih aromatskih ugljikovodika, polikloriranih bifenila te organoklorovih pesticida iz uzoraka tla raspršenjem tla kroz čvrstu fazu. Spojevi su to koji pokazuju izrazito negativne učinke na sve sastavnice okoliša što je posljedica njihove toksičnosti, dugotrajne postojanosti te lipofilne prirode koja uzrokuje njihovu migraciju iz vodenog medija u tlo. Iz tog razloga bitno je kvalitativno i kvantitativno odrediti navedene spojeve što je preduvjet za praćenje njihove prisutnosti i kretanja u okolišu. Metode kemijske analize koje se koriste u tu svrhu moraju biti izrazito osjetljive budući da se radi o nižim koncentracijama. Samim time i uzorci koji se analiziraju moraju biti visoko koncentrirani i čisti što zahtijeva dodatnu pripremu. U tu svrhu provedena je ekstrakcija raspršenjem tla kroz čvrstu fazu na kontrolnom uzorku tla. Parametri koji su se optimirali su: izbor čvrste faze (sorbensa), omjer tla i sorbensa te otapalo za eluiranje. Obzirom na dobivena iskorištenja, najboljim sorbensom pokazala se dijatomejska zemlja, najboljim omjerom tla i sorbensa omjer 1:4, a najboljim otapalom smjesa acetona i heksana u omjeru 1:1. Takva optimirana i validirana metoda primjenjena je na 10 realnih uzoraka tla iz okolice Zagreba. Dobivene vrijednosti koncentracija sve su redom niže od maksimalne dopuštene koncentracije koja je propisana Pravilnikom o zaštiti poljoprivrednog zemljišta od onečišćenja (NN 9/2014).In this paper, the extraction of organic pollutants from soil samples by dispersing the soil with the solid phase was studied. Specifically, polycyclic aromatic hydrocarbons, polychlorinated biphenyls and organochlorine pesticides were extracted. These are compounds that have extremely negative effects on all components of the environment, due to their toxicity, long-term stability and lipophilic nature, which causes the migration of the above pollutants from the water medium to the soil. For this reason, it is important to qualitatively and quantitatively determine the mentioned compounds, which in turn is then a prerequisite for monitoring their presence and movement in the environment. The chemical analysis methods used for this purpose must be extremely sensitive, since low concentrations are involved. Therefore, the samples for analysis must be highly concentrated and pure, which requires additional preparation. For this purpose, extraction was performed by dispersing a control soil sample with soil through the solid phase. The parameters that were optimized are: solid phase (sorbent), ratio of soil to sorbent and solvent for elution. Considering the obtained yields, the best sorbent was diatomaceous earth, the best ratio of soil to sorbent was 1:4, and the best solvent was a mixture of acetone and hexane in the ratio 1:1 This optimized and validated method was applied to 10 real soil samples from the surroundings of Zagreb. The obtained concentration values are all below the maximum value required by law