Table 4.

Intra-day and inter-day precision and accuracy of the method for umbilical plasma and placental tissue.

Bio-matrix	Analytea	Addedb concentration	Intra-day (n=6)			Inter-day (n=3)
			Mean concentration obtainedb	Mean accuracyc (%)	Precision (RSD, %)	Mean concentration obtainedb	Mean accuracyc (%)	Precision (RSD, %)
Umbilical cord plasma	BUP	0.250	0.220	88.1	11.3	0.237	94.7	10.4
		0.625	0.553	88.5	5.3	0.577	92.4	4.4
		62.5	59.2	94.7	6.2	60.8	97.3	4.4
		188	190	101.5	4.1	186.6	99.5	1.8
	OH-BUP	0.715	0.702	98.2	5.7	0.680	95.0	7.4
		1.79	1.77	98.9	5.7	1.774	99.2	1.8
		179	166	92.9	5.5	172.8	96.7	3.6
		536	512	95.5	2.2	519.0	96.8	2.0
	EB	0.245	0.239	97.7	5.3	0.234	95.7	6.4
		0.612	0.571	93.2	3.8	0.587	95.8	4.3
		61.2	57.1	93.3	6.0	58.8	95.9	3.1
		184	182	98.9	4.9	180.2	98.1	1.7
	TB	0.365	0.347	95.0	8.3	0.344	94.3	2.3
		0.912	0.860	94.2	4.8	0.873	95.7	2.1
		91.2	85.9	94.2	7.4	89.1	97.7	4.1
		274	266	97.1	5.0	266.4	97.3	1.1
Placental tissue	BUP	0.312	0.320	102.4	9.6	0.301	96.4	9.3
		0.625	0.605	96.8	8.8	0.605	96.8	7.7
		62.5	64.7	103.6	4.9	64.2	102.7	5.6
		188	185	98.5	8.6	185	98.8	7.4
	OH-BUP	0.895	0.811	90.7	12.0	0.839	93.8	12.5
		1.79	1.78	99.4	5.1	1.76	98.3	6.1
		179	188	105.1	4.1	182	101.8	6.4
		537	522	97.3	8.8	522	97.2	7.2
	EB	0.305	0.273	89.6	15.2	0.279	91.6	13.2
		0.610	0.597	97.9	8.8	0.587	96.3	8.3
		61.0	63.2	103.6	3.8	61.8	101.3	5.7
		183	181	98.7	8.4	180	98.5	7.4
	TB	0.918	0.856	93.3	11.5	0.858	93.5	11.2
		1.84	1.85	100.6	6.5	1.82	99.1	6.5
		184	193	105.3	4.1	190	103.5	5.4
		550	524	95.3	7.7	526	95.5	9.6

^aBUP=buproipion, OH-BUP=hydroxybupropion, EB=erythrohydrobupropion, TB=threohydrobupropion.

^bThe unit of analyte in umbilical cord plasma is ng/mL; the unit of analyte in placental tissue is ng/g.

^caccuracy=(obtained concentration/added concentration)×100