Determination of Formaldehyde by HPLC with Stable Precolumn Derivatization in Egyptian Dairy Products

Table 2

Precision contribution to the measurement uncertainty.

Contaminant	Commodity	Repeatability (%), RSD	Reproducibility (%), RSD#	Measurement uncertainty (%)
Formaldehyde	Cheese	4	8	± 25
	Milk	3	6	± 24
	Yogurt	6	9	± 26

: Relative standard deviation of repeatability was performed with n=6 by the same the personnel at the same time.
#: Relative standard deviation of reproducibility was performed with n=10 by different personnel at different times.