Spatial Variability of Metals in Surface Water and Sediment in the Langat River and Geochemical Factors That Influence Their Water-Sediment Interactions

Table 3

Average concentration (mg/kg) of metals in sediment analysis obtained from three replicates of the standard reference materials NIST, SRM 1646 (estuarine sediment).

Metals	Certified and estimated value	Measured value	Recovery (%)
As	6.23±0.21^a	5.73±0.72	91.92
Cd	0.148±0.007^a	0.17±0.05	111.59
Co	5.00^b	4.96±0.12	99.16
Cr	40.9±1.9^a	36.49±1.89	89.23
Ni	23.00^b	23.42±0.79	101.84
Pb	11.7±1.2^a	13.01±1.86	111.17

^aCertified value.
^bEstimated value.