A simple and inexpensive method for the determination of inorganic As(III) and As(V) at low ppb levels was developed. The method is based on formation of hydride from a sample solution and its reaction with mercury bromide on a solid support. Formation of a yellow-brownish product was optically detected. Amidosulfonic acid was used as a reaction medium for determination of total inorganic arsenic, while citrate buffer (0.1 mol/dm, pH=5.5) was used as a reaction media for determination of As(III) alone. As(V) was calculated as a difference of total inorganic arsenic and As(III). This method has been applied to soil extracts. Extraction of inorganic arsenic from soil samples was done in three-step sequential extraction with the following extractants: NH4H2PO4 (0.05 mol/dm); NH4-oxalate buffer (0.2 mol/dm, pH=3.25); and mixture of NH4-oxalate buffer (0.2 mol/dm) and ascorbic acid (0.1 mol/dm) at pH=3.25. The method was suitable for determination of inorganic arsenic species in soil extracts covering concentration range of the analyte between 0.2 20 ppb.

UDK 546.19:543.422.3 Razvijena je jednostavna i jeftina metoda za određivanje arsena u niskom ppb području. Metoda je zasnovana na redukciji arsenita i arsenata u kiseloj reakcionoj sredini do gasovitog produkta hidrida arsena, arsina i njegovoj reakciji sa živa(II) bromidom. Živa(II) bromid je impregniran na čvrsti nosač (filter papir), a formiranje i detekcija žuto-smeđeg produkta je vršena spektrofotometrijski, upotrebom instrumenta za terensko određivanje arsena, Supralab FD. Za podešavanje kiselosti rastvora korištena je amidosulfonska kiselina, a redukcija arsena je vršena natrij borhidridom. Metoda je korištena u određivanju arsena u uzorcima zemljišta nakon digestije. Validacija metode je izvršena upotrebom standardnog referentnog materijala (SRM 2710) i interlaboratorijskom komparacijom analizom sa ICP-MS. Limit detekcije razvijene metode je 0,06 mg As/dm3 sa limitom kvantifikacije od 0,2 mg As/dm3.

The flavonoid rutin (quercetin-3-rutinoside), is a flavonol glycoside comprised of the flavonol quercetin and the disaccharide rutinose. In this study, using HPLC-ED system, quantification of rutin was carried out in different extracts of medicinal plants. Analyses of rutin were performed with leaves and flowers of 50 medicinal plants of rue, buckwheat, rose, sage, calendula, chamomile, elder, dandelion, feverfew, lemon balm, linden, thyme, valerian, stinging nettle, cloves, dog rose, pansy, parsley, cowslip, rose etc. Rutin was extracted with hot water. Supernatant was used for analyses. The standard solution was 0.2 μg/20 μL rutin. Content of rutin (mg/g) was highest in the leaves of rue (86.0) followed by flowers of buckwheat (53.5), the leaves from buckwheat (20.0), flowers of pansy (33.5) and flowers of rose (10.0). In all other plants, the content of rutin was lower than 0.5 mg/g. The lowest content rutin (0.25 mg/g) was found in the leaves of lemon balm. The high concentration of rutin in flowers and leaves of rue, buckwheat, pansy and rose provided more importance to rue, buckwheat, pansy and rose as medicinal and diet plants.