CN113358631A - ICP (inductively coupled plasma) determination method for effective phosphorus in soil - Google Patents

Abstract

The invention discloses an ICP (inductively coupled plasma) determination method for soil available phosphorus, which aims to establish the ICP determination method for the soil available phosphorus, and the ICP determination method comprises the steps of weighing 5.00g of an air-dried sample passing through a 2mm sieve pore by adopting acid soil, placing the air-dried sample into a 200ml plastic bottle, adding 50ml of ammonium fluoride-hydrochloric acid leaching liquor, oscillating for 30min (oscillation frequency is 180 +/-20 r/min) at 25 +/-1 ℃, carrying out centrifugal filtration, weighing 2.00g of the air-dried sample passing through the 2mm sieve pore and placing the air-dried sample into a 200ml plastic bottle, adding 50ml of sodium bicarbonate leaching liquor, oscillating for 30min (oscillation frequency is 180 +/-20 r/min) at 25 +/-1 ℃ by using a computer for determination, carrying out centrifugal filtration, and carrying out computer-determination for drawing a standard curve: respectively transferring 5ug/mlP standard solution 0ml, 2.5ml, 5ml, 10ml, 15ml and 20ml into a 50ml volumetric flask, metering the volume of the acidic soil with ammonium fluoride-hydrochloric acid leaching liquor, and metering the volume of the neutral and calcareous soil with sodium bicarbonate leaching liquor.

Description

ICP (inductively coupled plasma) determination method for effective phosphorus in soil

(1) Field of the invention

The invention belongs to the field of environment, and relates to a quantitative analysis technology for soil available phosphorus

(2) Background of the invention

Phosphorus is one of essential major elements of plants, the content of total phosphorus in the cultivated land soil in China is 0.17-1.09 g/kg, and the content of phosphorus in most of soil is 0.43-0.66 g/kg. People generally solve the problem that the phosphorus in soil cannot meet the growth requirement of plants by applying a phosphate fertilizer. The phosphate fertilizer applied to the soil cannot be completely utilized by plants, and most of the phosphate fertilizer is fixed by the soil and then is converted into a part of a soil phosphorus reservoir. Factors affecting the phosphorus content in the soil include the parent soil, the process of soil formation, tillage fertilization, etc

Soil available phosphorus: the phosphorus component which can be absorbed by plants in the soil comprises all water-soluble phosphorus, part of adsorbed phosphorus and organic phosphorus, and some soils also comprise some precipitated phosphorus. Chemically, available phosphorus is defined as: phosphorus that is isotopically exchanged with 32P or easily extracted by certain chemical agents, and phosphates in soil solutions. Although the acquisition of phosphorus seems to be wide, most of phosphorus in the natural environment can not be absorbed by plants, and a phosphate fertilizer is needed to supplement the requirement of plants on phosphorus elements. Guiding scientific fertilization. Has great significance in improving the crop yield

The phosphorus supply condition of the soil is expressed by the effective phosphorus content of the soil. The effective phosphorus content of the soil determined by a chemical method is a relative index for evaluating the phosphorus supply capacity of the soil, and is an important basis for reasonably applying a phosphate fertilizer.

Soil available phosphorus is generally measured by NY-T1121.7-2014 standard by adopting a spectrophotometric method, organic matters are dissolved due to the relationship of the used leaching liquor, so that the leaching liquor is yellow (brown) and the color of the leaching liquor becomes dark along with the increase of the content of the organic matters, thereby influencing colorimetric analysis. Various agents are required to eliminate interference. And meanwhile, the temperature, acidity and time for developing color are well controlled, otherwise, the measurement result is influenced. The sample is directly tested on a machine after being extracted by ultrasonic waves, and the sample does not need to be processed again. Fast, accurate and saves many chemical reagents. And the cost is saved. Is suitable for large-batch analysis work.

The method establishes ICP measurement of available phosphorus in soil

(3) Content providing method and apparatus

The purpose is as follows: an ICP determination analysis method which is accurate in operation, rapid, good in stability and easy to master the available phosphorus in the soil is formulated.

The technical scheme is as follows:

the invention relates to an ICP (inductively coupled plasma) determination and analysis method for effective phosphorus in soil.

The method comprises the following steps:

acid soil

Weighing 5.00g of sample air-dried through a 2mm sieve pore, placing in a 200ml plastic bottle, adding 50ml of ammonium fluoride-hydrochloric acid leaching liquor in ultrasonic waves at 25 +/-1 ℃, performing ultrasonic treatment for 10 minutes, performing centrifugal filtration, and performing on-machine determination

Neutral, calcareous soil sample (PH ≧ 6.5)

Weighing 2.00g of sample air-dried through a 2mm sieve pore, placing in a 200ml plastic bottle, adding 50ml of sodium bicarbonate leaching liquor, performing ultrasonic treatment at 25 + -1 deg.C for 10 min, centrifuging, filtering, and measuring with a computer

Drawing a standard curve: respectively transferring 5ug/mlP standard solution 0ml, 2.5ml, 5ml, 10ml, 15ml and 20ml into a 50ml volumetric flask, metering the volume of the acidic soil with ammonium fluoride-hydrochloric acid leaching liquor, and metering the volume of the neutral and calcareous soil with sodium bicarbonate leaching liquor.

(4) Advantageous effects

Accurate and stable: the method is rapid, stable in measurement result and accurate in data. And the sample is saved.

(5) Detailed description of the preferred embodiments

Acid soil

Weighing 5.00g of sample air-dried through a 2mm sieve pore, placing in a 200ml plastic bottle, adding 50ml of ammonium fluoride-hydrochloric acid leaching liquor in ultrasonic waves at 25 +/-1 ℃, performing ultrasonic treatment for 10 minutes, performing centrifugal filtration, and performing on-machine determination

Neutral, calcareous soil sample (PH ≧ 6.5)

Weighing 2.00g of sample air-dried through a 2mm sieve pore, placing the sample in a 200ml plastic bottle, adding 50ml of sodium bicarbonate leaching liquor into ultrasonic waves at 25 +/-1 ℃, performing ultrasonic treatment for 10 minutes, performing centrifugal filtration, and performing measurement on a computer

Drawing a standard curve: respectively transferring 5ug/mlP standard solution 0ml, 2.5ml, 5ml, 10ml, 15ml and 20ml into a 50ml volumetric flask, metering the volume of the acidic soil with ammonium fluoride-hydrochloric acid leaching liquor, and metering the volume of the neutral and calcareous soil with sodium bicarbonate leaching liquor.

1. The method comprises the following steps:

acid soil

Weighing 5.00g of sample air-dried through a 2mm sieve pore, placing in a 200ml plastic bottle, adding 50ml of ammonium fluoride-hydrochloric acid leaching liquor in ultrasonic waves at 25 +/-1 ℃, performing ultrasonic treatment for 10 minutes, performing centrifugal filtration, and performing on-machine determination

Neutral, calcareous soil sample (PH ≧ 6.5)

Weighing 2.00g of sample air-dried through a 2mm sieve pore, placing the sample in a 200ml plastic bottle, adding 50ml of sodium bicarbonate leaching liquor into ultrasonic waves at 25 +/-1 ℃, performing ultrasonic treatment for 10 minutes, performing centrifugal filtration, and performing measurement on a computer

Drawing a standard curve: respectively transferring 5ug/mlP standard solution 0ml, 2.5ml, 5ml, 10ml, 15ml and 20ml into a 50ml volumetric flask, metering the volume of the acidic soil with ammonium fluoride-hydrochloric acid leaching liquor, and metering the volume of the neutral and calcareous soil with sodium bicarbonate leaching liquor.

2. Instruments and reagents:

2.1 electronic balance: 0.01g

2.2 inductively coupled plasma emission Spectroscopy Thermo iCAP 7000SERIES

2.3 ammonium fluoride-hydrochloric acid leach liquor, 1.11g of ammonium fluoride is weighed and dissolved in 400ml of water, 2ml of concentrated hydrochloric acid is added, and the volume is determined to be 1L by using water. Storing in plastic bottle.

2.4 sodium hydroxide solution 100g/L:

2.5 sodium bicarbonate leach liquor: 42.0g of sodium bicarbonate are weighed out and dissolved in 600ml of water, the pH is adjusted to 8.5 with sodium hydroxide (100g/L), the solution is diluted to 1L with water and stored in a plastic bottle.

2.65 ug/ml P standard solution

3 conditions of the apparatus

Speed of pump	45rpm
		Power of	1150W
Auxiliary gas flow	0.5L/min
		Observation mode	Horizontal observation
Integration time	5s
		Time of sample washing	30s
Measuring wavelength (nm)	213.618

4 test method:

analytical procedure

Acid soil

Weighing 5.00g of sample air-dried through a 2mm sieve pore, placing in a 200ml plastic bottle, adding 50ml of ammonium fluoride-hydrochloric acid leaching liquor in ultrasonic waves at 25 +/-1 ℃, performing ultrasonic treatment for 10 minutes, performing centrifugal filtration, and performing on-machine determination

Neutral, calcareous soil sample (PH ≧ 6.5)

Weighing 2.00g of sample air-dried through a 2mm sieve pore, placing the sample in a 200ml plastic bottle, adding 50ml of sodium bicarbonate leaching liquor into ultrasonic waves at 25 +/-1 ℃, performing ultrasonic treatment for 10 minutes, performing centrifugal filtration, and performing measurement on a computer

Drawing a standard curve: respectively transferring 5ug/mlP standard solution 0ml, 2.5ml, 5ml, 10ml, 15ml and 20ml into a 50ml volumetric flask, metering the volume of the acidic soil with ammonium fluoride-hydrochloric acid leaching liquor, and metering the volume of the neutral and calcareous soil with sodium bicarbonate leaching liquor.

Accuracy:

name of article	Measured value (mg/kg)	Standard value (mg/kg)	Uncertainty (mg/kg)	Great difference (mg/kg)
					Shanxi yellow cotton soil GBW07460(ASA-9)	23.6	24	±3	-0.4

Accuracy of

Name of article	Measured value of the method (mg/kg)	NY/T1121.7-2014 (mg/kg)
			Soil TR190869-1	4.5	4.6
Soil TR190869-2	6.8	6.8
			Soil TR190869-3	7.3	7.2

As can be seen from the above table: the measured data has high accuracy

Precision degree

Name of article	Measured value (mg/kg)
		Soil TR190869-1	4.5 4.5 4.6 4.5 4.6 4.6 4.5 4.5

As can be seen from the above table: the measured data has high precision

(6) The conclusion is that:

by the method, the content of the available phosphorus in the soil can be accurately determined, and the blank of an ICP (inductively coupled plasma) determination analysis method for the available phosphorus in the soil is filled. Is suitable for large-scale detection and analysis. The application in production achieves better effect.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention and are intended to limit the scope of the present invention, and various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention are intended to fall within the scope of the present invention defined by the claims.

Claims (3)

1. The ICP determination method of the available phosphorus in the soil comprises the following steps:

the method is characterized by comprising the following steps:

acid soil

Weighing 5.00g of sample air-dried through a 2mm sieve pore, placing in a 200ml plastic bottle, adding 50ml of ammonium fluoride-hydrochloric acid leaching solution, oscillating at 25 + -1 deg.C for 30min (oscillation frequency 180 + -20 r/min), centrifuging, filtering, and measuring on a computer.

Neutral, calcareous soil sample (PH ≧ 6.5)

Weighing 2.00g of sample air-dried through a 2mm sieve pore, placing in a 200ml plastic bottle, adding 50ml of sodium bicarbonate leaching liquor, oscillating at 25 +/-1 ℃ for 30min (oscillation frequency is 180 +/-20 r/min), centrifuging, filtering, and measuring on a machine.

2. The ICP method for measuring available phosphorus in soil according to claim 1.

The method is characterized in that:

drawing a standard curve: respectively transferring 5ug/mlP standard solution 0ml, 2.5ml, 5ml, 10ml, 15ml and 20ml into a 50ml volumetric flask, metering the volume of the acidic soil with ammonium fluoride-hydrochloric acid leaching liquor, and metering the volume of the neutral and calcareous soil with sodium bicarbonate leaching liquor.

3. The ICP method for measuring available phosphorus in soil according to claim 2.

The method is characterized in that: a constant temperature reciprocating oscillator, 5ug/mlP standard solution and ICP.