Preparation Of Soil Extract B; Photometric Determination Of Phosphorus - MACHEREY-NAGEL VISOCOLOR Manual

Preprogrammed submethods:
Wavelength: 660 nm
Method 0031 0.04–2.30 mg/L NH
Method 0032 0.05–3.00 mg/L NH
Method 0036 0.08–4.60 mg N/kg soil
Method 0041 0.2–8.0 mg/L NH
Method 0042 0.2–10.0 mg/L NH
Method 0046 0.4–16.0 mg N/kg soil
Method 0051 1.0–40.0 mg/L NH
Method 0052 1.0–50.0 mg/L NH
Method 0056 2.0–80.0 mg N/kg soil
Procedure with further NANOCOLOR
Measurement of ammonium nitrogen with the reagent sets
®
NANOCOLOR Ammonium 10 / 50 (REF 985004 / 985005):
Follow the instructions enclosed in the reagent set. If soil extract
AF is turbid, it must be filtered with a 0.45 μm membrane filter
(REF 91650) 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
® UV UV
NANOCOLOR / , /
VIS VIS
Plus
PF-12 , PF-12
Wavelength 690 nm
Test 0–04 Method 0046
Method 0047
Test 0–05 Method 0056 (bar-code reading photometers)
Method 0057 (bar-code reading photometers)
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
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 flocs 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 sufficient 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 briefly. Place plastic funnel
in a 100 mL measuring cylinder, insert a folded filter MN 616 ¼.
Filter suspension. If the solution is initially turbid, pour it back into
the folded filter. A slightly yellow inherent color of soil extract B
will not affect the following analysis.
Manual VISOCOLOR
Manual VISOCOLOR
-N
4
4
-N
4
4
-N
4
4
®
photometers
®
photometers
II, VIS, VIS II, 500 D, 400 D,
0,4–16 mg N/kg soil
1.8–72 kg N/ha soil
2–80 mg N/kg soil
9–360 kg N/ha soil
3
), is used to ana-
®
reagent case for soil analysis 02.19
®
reagent case for soil 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
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
Add 6 drops PO –2 (50), seal the glass and shake. Clean outside
4
of test tube and measure after 10 min with the PF-3 (40).
1
2
3
4
5
ml
PO -1
4
51 13 49
Preprogrammed submethods:
Wavelength: 660 nm
Method 5841 0.2–5.0 mg/L PO
Method 5842 0.6–15.0 mg/L PO
Method 5847 5–115 mg/100g P
Method 5849 20–500 mg P/kg soil
Measurement of phosphorus with reagent set NANOCOLOR
Phosphate 5 / 15 (REF 985081 / 985080) 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
Method 0803 0.7–34.5 mg/L P
Method 0804 0.7–34.5 mg/L P
Method 0805 0.30–15.00 mg/L PO
Method 0806 1.0–45.0 mg/L PO
Method 0807 1.4–69.0 mg/100g P
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
Method 0815 0.20–5.00 mg/L PO
Method 0816 0.5–15.0 mg/L PO
Method 0817 0.9–23.0 mg/100 g P
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.
®
ECO Phosphate test kit needs
–1 (49), seal the glass and shake.
4
PO -2
4
50 40
-P*
4
*
4
O
2 5
(total-Phosphate)
4
O (total-Phosphate)
2 5
O (ortho-Phosphate)
2 5
–P (ortho-Phosphate)
4
3–
(ortho-Phosphate)
4
O (CAL)
2 5
3–
4
-P (ortho-Phosphate)
4
3–
(ortho-Phosphate)
4
O (CAL)
2 5
®
®
29