抄録
The two methods of water elimination, centrifugation and air-drying, from sediments (river, lake, marine) were compared for analytical variation to establish sample preparation methods. Fourteen analytes elements (4 determinations × 10 points) were tested for this purpose.
Mean analytical values of lead, moisture content, cadmium, mercury and CODsed for some of sediment samples differed by more than 10% between two methods.
The t test results indicated that copper, CODsed, pH and moisture content had significant differences between two methods at the 5% level.
Coefficients of variation of lead, cadmium and CODsed in centrifuged method became often greater than 10%. This is because mixing of centrifuged sediment after water elimination is difficult. On the other hand, low coefficients of variation in air-dried sediments were obtained because of easy mixing.
Therefore, air-dried sample is superior to centrifuged sample with regard to homogeneity and handling.
Air-drying for a day was sufficient practicaly.
