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Table 2015.18E. ICP-OES calibration standards from stock reagent salts for “total” P and K
Standard
ID
Vol.,
mL
Acid,
mL
a
Weight
NH
4
H
2
PO
4
, g
Weight
KCl, g
P concn,
µg/mL
P
2
O
5
,
µg/mL
P
2
O
5
,
solution,
%
P
2
O
5
,
sample,
%
K concn,
µg/mL
K
2
O,
µg/mL
K
2
O
solution,
%
K
2
O
sample,
%
Blank
1000
40
0
0
0
0
0
0
0
0
0
0
1
1000
40
40 of Standard 6
b
0.6305
9.8
22.4
0.00224
1
332
400
0.0400
20
2
1000
36
100 of Standard 10
b
0.4748
47
108
0.01076
5
249
300
0.0300
15
3
500
12
100 of Standard 10
b
100 of Standard 14
b
94
215
0.02153
11
163
196
0.0196
10
4
1000
32
0.4539
200 of Standard 12
b
122
280
0.02802
14
116
140
0.0140
7
5
1000
36
0.6810
100 of Standard 14
b
184
420
0.04204
21
81
98
0.0098
5
6
1000
40
0.9079
50 of Standard 13
b
245
561
0.05605
28
34.9
42
0.0042
2
7
1000
40
1.1349
25 of Standard 13
b
306
701
0.07007
35
17.4
21
0.0021
1
8
1000
40
1.3619
NA
c
367
841
0.08408
42
NA
NA
NA
NA
9
1000
40
1.5888
NA
428
981
0.09809
49
NA
NA
NA
NA
10
1000
40
1.7510
NA
472
1081
0.10811
54
NA
NA
NA
NA
11
1000
40
NA
0.7915
NA
NA
NA
NA
415
500
0.0500
25
12
1000
40
NA
1.1079
NA
NA
NA
NA
581
700
0.0700
35
13
1000
40
NA
1.3295
NA
NA
NA
NA
697
840
0.0840
42
14
1000
40
NA
1.5511
NA
NA
NA
NA
814
980
0.0980
49
15
1000
40
NA
1.7727
NA
NA
NA
NA
930
1120
0.1120
56
16
1000
40
NA
1.9943
NA
NA
NA
NA
1046
1260
0.1260
63
17
1000
40
0.9728
0.9497
262
601
0.06006
30
498
600
0.0600
30
a
Acid = Volume of 1:2 HCl–water required to make standard.
b
Serial dilution from another standard (e.g., 40 of Standard 6 means add 40 mL of Standard 6).
c
NA = Not applicable.
Table 2015.18F. Calibration criteria for acid-soluble or “total” P and K
Element ID
Wavelength, nm
a
Calibration range, µg/mL
Standards used (
see
Table
2015.18D
) Curve fit
Spectral deconvolution
P
213.618 (1)
0 to 245
Blank, 1, 2, 3, 4, 5, 6
Linear
Cu 213.598
P
213.618 (2)
184 to 472
5, 6, 7, 8, 9, 10
Linear
Cu 213.598
P
214.914 (1)
0 to 245
Blank, 1, 2, 3, 4, 5, 6
Linear
Cu 214.898
P
214.914 (2)
184 to 472
5, 6, 7, 8, 9, 10
Linear
Cu 214.898
K
766.485 (1)
0 to 332
Blank, 1, 2, 3, 4, 5, 6, 7
Linear
None
K
766.485 (2)
332 to 1046
11, 12, 13, 14, 15, 16, 17
Linear
None
K
769.897 (1)
0 to 332
Blank, 1, 2, 3, 4, 5, 6, 7
Linear
Possible LiNO
3
K
769.897 (2)
332 to 1046
11, 12, 13, 14, 15, 16, 17
Linear
Possible LiNO
3
a
(1) and (2) distinguish between the same wavelength used to cover two separate concentration ranges.
Candidates for 2016 Method of the Year
259