RESUMO
Eleven mineral-elements, Mg, Fe, K, Ca, Mn, Zn, Cu, Ni, Pb, Cr and Cd, for eight benthic marine diatoms were determined by using flame atomic absorption spectrophotometry (AAS). This method is rapid with high precision and accuracy. The relative standard deviation, correlative coefficient and recovery rate are less then 6.85%, 0.9989-0.9999 and 95%-103%, respectively. The results show that there are high mineral-element levels in the eight benthic diatoms, with Mg>Fe>K>Ca> Mn>Zn among them, while the contents of Ni and Cu are poor, and there are little Pb, Cr and Cd in benthic diatoms. The contents of Mg, K and Mn in Navicula seminulum Grun are maximum elements, with (17.2240 +/- 0.0302) mg x g(-1) SD and (1.7885 +/- 0.0939) mg x g(-1) SD, (0.2253 +/- 0.0011) mg x g(-1) SD respectively. There were the most contents of Fe (4.2314 +/- 0.0309) mg x g(-1) SD and Zn (0.1167 +/- 0.0029) mg x g(-1) SD, Cu (0.0227 +/- 0.0007) mg x g(-1) SD and Ni (0.0147 +/- 0.0005) mg x g(-1) SD in Hantzschia amphioxys (Ehr.) Grun. var. leptocephala Ostrup. The element of maximum content in Nitzschia sp. was Ca (6.3537 +/- 0.0412 mg x g(-1) SD). The experimental results indicate that the eight benthic diatom species could prove useful feed species for benthic animal species grown in aquaculture such as abalone, sea urchin and sea cucumber.