Table 6.

Summary of uncertainties obtained for the test analytes using the top-down approach.

Analyte	ur,repro (%)	Br (%)	ur,cm (%)	ur,ref (%)	ur,tot (%)	Ur,tot (%)
Hexachloro-1,3-butadiene	8.01	−4.66	0.909	1.15	9.38	18.8
Pentachlorobenzene	9.90	−5.15	0.676	0.250	11.2	22.4
alpha-HCH	7.83	−10.6	0.154	0.475	13.2	26.3
Hexachlorobenzene	8.42	7.38	0.274	1.00	11.2	22.5
beta-HCH	8.13	−11.6	0.954	0.150	14.2	28.4
Lindane	6.04	−13.0	0.451	0.866	14.4	28.7
delta-HCH	7.15	−9.40	1.34	0.330	11.9	23.8
Heptachlor	7.60	−6.23	2.74	0.250	10.2	20.4
BDE-28	6.48	−1.28	2.78	0.295	7.18	14.4
BDE-47	7.98	1.90	1.56	0.300	8.36	16.7
BDE-100	9.75	0.192	0.913	0.300	9.80	19.6
BDE-99	8.01	−0.879	2.06	0.300	8.32	16.6
BDE-154	8.50	1.17	2.89	0.300	9.06	18.1
BDE-153	9.00	5.08	3.50	0.300	10.9	21.8

Abbreviations: u_r,repro—within-lab reproducibility; B_r—relative bias; u_r,cm—uncertainty of systematic error; u_r,ref—uncertainty of purity of analytical standard; u_r,tot—relative combined measurement uncertainty; U_r,tot—expanded combined measurement uncertainty.