Macherey-Nagel Visocolor - Preparation of Soil Extract B; Photometric Determination of Phosphorus

Manual VISOCOLOR
®
reagent case for soil analysis
33
Manual VISOCOLOR
®
reagent case for soil analysis 03.14
MN
Preprogrammed submethods:
Wavelength: 660 nm
Method 0031 0.04–2.30 mg/L NH
4
-N
Method 0032 0.05–3.00 mg/L NH
4
Method 0036 0.08–4.60 mg N/kg soil
Method 0041 0.2–8.0 mg/L NH
4
-N
Method 0042 0.2–10.0 mg/L NH
4
Method 0046 0.4–16.0 mg N/kg soil
Method 0051 1.0–40.0 mg/L NH
4
-N
Method 0052 1.0–50.0 mg/L NH
4
Method 0056 2.0–80.0 mg N/kg soil
Procedure with further NANOCOLOR
®
photometers
Measurement of ammonium nitrogen with the reagent sets
NANOCOLOR
®
Ammonium 10 / 50 (REF 985 004 / 985 005):
Follow the instructions enclosed in the reagent set. If soil extract
AF is turbid, it must be ltered with a 0.45 μm membrane lter
(REF 916 50) prior to analysis. The selection of the test depends
on the ammonium content to be expected. For higher contents,
use the test 0-05, for lower levels test 0-04.
Preprogrammed NANOCOLOR
®
photometers
NANOCOLOR
® UV
/
VIS
, VIS, 500 D, 400 D, 300 D, 250 D, PF-12
Wavelength 690 nm
Test 0-04 Method (0)046 0,4–16 mg N/kg soil
Method (0)047 1.8–72 kg N/ha soil
Test 0-05 Method 0056 (bar-code reading photometers) or
048 2–80 mg N/kg soil
Method 0057 (bar-code reading photometers) or
049 9–360 kg N/ha soil
Other photometers
Wavelength 690
nm
Test 0-04 Multiply displayed result in mg/L with 2:
0.4–16 mg N/kg soil
Test 0-05 Multiply displayed result in mg/L with 2:
2–80 mg N/kg soil
3.6 Preparation of soil extract B
Soil extract B, which is prepared with extraction solution B (CAL
solution = calcium acetate lactate, 0.05
mol/dm
3
), is used to ana-
lyze phosphorus and potassium.
Preparation of the extraction solution:
Pour 2 x 100 mL of the CAL stock solution into the bottle for ex-
traction solution B, add 0.8
L of distilled water and mix (or mix
100 mL CAL stock solution with 400 mL distilled water).
Note: Should ocs or precipitates occur in the extraction solution
B, the solution is to be discarded. Rinse the bottle several times
with hot water and prepare fresh solution.
Preparation of the soil extract:
Normally, the soil should be dried at 105 °C for the purpose of
removing the soil water. However, since a drying oven will rarely
be available, it is sufcient to dry the soil overnight at room tem-
perature. Weigh out 10 g of the air-dried, screened soil in a shak-
ing bottle. Add 200 mL of extraction solution B with the aid of the
measuring cylinder, close shaking bottle. Shake bottle vigorously
for 5 min, allow solid matter to settle briey. Place plastic funnel
in a 100 mL measuring cylinder, insert a folded lter MN 616 ¼.
Filter suspension. If the solution is initially turbid, pour it back into
the folded lter. A slightly yellow inherent color of soil extract B
will not affect the following analysis.
3.7 Photometric determination of phosphorus
Procedure with PF-3:
Measurement of phosphorus with reagent set VISOCOLOR
®
ECO Phosphate and the PF-3:
The use of the VISOCOLOR
®
ECO Phosphate test kit needs
for a dilution of extract B (1+4). Zero measurement with sample.
Rinse test tube (51) and add 5 mL water sample using the plastic
syringe (13). Add 6 drops PO
4
-1 (49), seal the glass and shake.
Add 6 drops PO
4
-2 (50), seal the glass and shake. Clean outside
of test tube and measure after 10 min with the PF-3 (40).
1
2
3
4
5
ml
B.BRAUN
Neumann-Neander-Str. 6–8 · 52355 Düren
Germany · Tel.: +49 24 21 969-0
PO
4
-1
6 x
Neumann-Neander-Str. 6–8 · 52355 Düren
Germany · Tel.: +49 24 21 969-0
PO
4
-2
6 x
504951 13 40
Preprogrammed submethods:
Wavelength: 660 nm
Method 5841 0.2–5.0 mg/L PO
4
-P*
Method 5842 0.6–15.0 mg/L PO
4
*
Method 5847 5–115 mg/100g P
2
O
5
Method 5849 20–500 mg P/kg soil
Measurement of phosphorus with reagent set NANOCOLOR
®
Phosphate 5 / 15 (REF 985 081 / 985 080) and the PF-3:
Follow the instructions enclosed in the reagent set.
Preprogrammed submethods
Wavelength: 660 nm
Method 0801 0.30–15.00 mg/L P (total-Phosphate)
Method 0802 1.0–45.0 mg/L PO
4
(total-Phosphate)
Method 0803 0.7–34.5 mg/L P
2
O
5
(total-Phosphate)
Method 0804 0.7–34.5 mg/L P
2
O
5
(ortho-Phosphate)
Method 0805 0.30–15.00 mg/L PO
4
–P (ortho-Phosphate)
Method 0806 1.0–45.0 mg/L PO
4
3–
(ortho-Phosphate)
Method 0807 1.4–69.0 mg/100g P
2
O
5
(CAL)
Method 0808 60–1560 kg/ha (CAL)
Method 0809 6–300 mg P/kg soil (CAL)
Method 0811 0.20–5.00 mg/L P
Method 0812 0.5–15.0 mg/L PO
4
3–
Method 0815 0.20–5.00 mg/L PO
4
-P (ortho-Phosphate)
Method 0816 0.5–15.0 mg/L PO
4
3–
(ortho-Phosphate)
Method 0817 0.9–23.0 mg/100 g P
2
O
5
(CAL)
Method 0819 4–100 mg P/kg soil (CAL)
*In case of using this submethods for soil analysis, the dilution has to be corrected manually.