Table 4.

Results of individual and global uncertainties for each herbicides

Herbicides	Calibration curve	Precision		Bias		aGlobal uncertainty	aExpanded uncertainty
	U1	U2	U3	U4	U5	(U)	(2U)
Pendimethalin	1.2	2.44	1.5	1.99	1.2	3.88	7.76
Oxyfluorfen	3.45	2.32	1.89	1.82	1.51	5.14	10.28
Imazethapyr	2.52	1.83	1.75	1.28	1.16	3.97	7.94
Quizalofop-p-ethyl	1.05	2.31	1.54	1.79	1.23	3.68	7.36

^aUncertainty components (expressed as relative measures, calculated at 50 ng g⁻¹)