Initial Reports Volume 187
Chapter 2, Table T5. X-ray fluorescence trace element analytical accuracy and precision.

Note: Precision has been estimated from means (in parts per million, except for TiO2) and from standard deviations (SD) of repeated analyses of the reference standards BIR-1 and MRG-1 following the final calibration. * = Govindaraju (1994). RSD = relative standard deviation.

	Date 	Trace element (ppm)											
Run	(Dec 1999)	Nb	Zr	Y	Sr	Rb	Zn	Cu	Ni	Cr	V	Ce	Ba
BIR-1													
Recommended value*		1	16	16	108	0	71	126	166	382	313	2	7
2	5	2	19	16	108	0	72	126	162	420	306	2	80
3	6	3	18	17	108	1	73	125	159	427	306	4	79
4	7	4	19	17	108	0	72	124	159	432	315	6	78
5	10	3	19	17	108	0	72	125	160	432	315	5	78
6	11	4	19	17	108	0	71	124	157	429	312	6	77
7	13	3	19	17	108	0	71	124	161	395	313	7	4
8	16	4	19	17	108	0	72	125	157	351	257	7	24
	Average:	3	19	17	108	0	72	125	159	412	303	5	60
	1 SD:	1	0	0	0	0	1	1	2	30	21	2	32
	%RSD:	23	2	2	0	143	1	1	1	7	7	30	53

MRG-1													
Recommended value*		20	108	14	266	9	191	134	193	430	526	26	61
2	5	19	99	14	255	6	189	126	177	525	528	32	47
3	6	21	99	14	254	6	188	126	179	518	510	32	46
4	7	21	100	14	254	7	188	125	178	525	514	33	45
5	10	21	100	14	254	7	186	126	178	525	512	32	46
6	11	22	99	13	254	6	185	126	176	519	489	30	52
7	13	20	98	14	255	7	186	126	180	437	497	32	54
8	16	20	99	14	254	6	185	126	177	444	558	30	60
	Average:	21	99	14	254	6	187	126	178	499	515	32	50
	1 SD:	1	1	1	1	0	1	0	1	40	23	1	6
	%RSD:	4	1	4	0	7	1	0	1	8	4	4	12