CN103630599A - Method for measuring potassium content in humic acid and humates by ICP-MS - Google Patents

Abstract

A method for measuring potassium content in humic acid and humates by ICP-MS comprises: employing a microwave digestion method to perform pre-processing on humic acid and humates; establishing an inductively coupled plasma mass spectrum method (ICP-MS method) for determining potassium element in humic acid and humates by improving the conditions of microwave digestion and optimizing ICP-MS determination parameters; and analyzing data by a work station software, drafting a standard curve and calculating the sample content. The microwave digestion method is an efficient reliable sample pre-processing method, and has the characteristics of being thorough in digestion, rapid and simple, less in acid consumption, avoided in loss and pollution, and the like. The inductively coupled plasma mass spectrum method (ICP-MS method) for analyzing potassium has the advantages of being high in sensitivity, good in stability, wide in dynamic linearity scope (capable of crossing 9 orders of magnitudes), fast in analysis speed, capable of multi-element simultaneous analysis, and the like, and is capable of substantially shortening the detection period of potassium in humic acid and humates and improving the result accuracy, and the environmental pollution is small.

Description

A kind of ICP-MS measures the method for potassium content in humic acid and humate

Technical field

The invention belongs to ICP-MS method and measure the technical field of constituent content, what specifically relate to is the method for measuring potassium content in humic acid and humate.

Background technology

Humic acid material is the material of the ecosystem and a junction of energy circulation, plays the basic transfer effect of forming a connecting link, and makes biosphere state in relative equilibrium within the quite a long time of the earth.Humic acid is comprised of multiple elements such as carbon, hydrogen, oxygen, nitrogen, sulphur, the trace element such as k adsorption, ammonium, magnesium, iron in a large number, it not only has the multi-function action of farm manure, has again the quick-acting feature of chemical fertilizer, so be called as a kind of multi-functional organic composite fertilizer simultaneously

In the recent period, professor Li Zuohu of process institute of the Chinese Academy of Sciences proposes to utilize artificial chemistry analogy method to realize " the artificial closed cycle of organism " and " the artificial closed cycle of inorganics ", the new concept of " ecological chemical industry " is old, and apply soda acid coproduction and reprocessing cycle new principle, the artificial chemistry that has proposed humic acid substance transforms new principle and new method.A vital role of the method is nontoxic by agricultural organic waste (as maize straw, straw, sawdust etc.) exactly, odorless, promptly change into NPK----humic acid complex fertilizer, to create the new industry of humic acid complex fertilizer, replace existing inorganic composite fertilizer industry, form intensive " the sustainable agriculture garden " that with plant husbandry, aquaculture, forestry etc., be integrated.In this new model, both broken away from the shade of oil-agriculture, jumped out again the petty-farmer management pattern of Traditional Organic Agriculture, for building, new agriculture-countryside-farmer provides a kind of new technological paradigm, and be the lifting to existing " ecological agriculture " matter.

Now, humic acid and humate are improving chemical fertilizer utilization ratio, improvement soil, are increasing the anti-adversity of crop and improve the aspects such as agricultural product quality and obtained remarkable progress and be subject to gradually people's attention, humic acid and humate be widely used in agricultural, medicine, industry, etc. in industry, meanwhile, it also can be used as green feed additive.

Potassium is the important trace element in humic acid and humate, its content is the important indicator of weighing humic acid and humate, people are a lot of to the analytical approach of potassium at present, for the higher method of the accuracy of analysis of potassium, it is tetraphenyl borate potassium gravimetric method, the method operation steps is numerous and diverse, result poor reproducibility, analysis time is long, is not suitable for the simple and efficient requirement of current detection technique.

Summary of the invention

The object of the invention is research and with ICP-MS, measure the method for potassium content in humic acid and humate, adopt Microwave Digestion to carry out pre-treatment to humic acid and humate, by improving micro-wave digestion condition, optimize ICP-MS location parameter, set up inductively coupled plasma mass spectrometry (ICP-MS method) and detected the potassium element in humic acid and humate.By workstation software, analyze data, drawing standard curve, calculation sample content.

Micro-wave digestion is a kind of efficient, method of sample pre-treatments reliably, have clear up thorough, rapid and simple, sour consumption few, avoid loss and the feature such as stain.

Inductively coupled plasma mass spectrometry (ICP-MS) analyzes that potassium has highly sensitive, good stability, dynamic linear wide ranges (can across 9 orders of magnitude), analysis speed is fast and multielement such as analyzes at the advantage simultaneously, can greatly shorten the sense cycle of potassium in humic acid and humate, improved result accuracy, and environmental pollution is little.

Embodiment

One, experimental technique

1. the preparation of sample

(1) fluid sample

Sample is fully mixed, directly use.

(2) solid sample

Sample is placed in to FOSS Knifetec1095 grinding machine for grinding and mixes, standby.

2. the digestion of sample

Accurately take sample 0.5g (being accurate to 0.0001g) and be placed in digestion tube, add 10mL red fuming nitric acid (RFNA), put into microwave dissolver and digest, clear up program in Table 1.Be cooled to after room temperature, with ultrapure water, be transferred to the volumetric flask of 100ml, constant volume, standby.Shake up standbyly, do reagent blank simultaneously.

The program design of table 1 microwave digestion

Divide and get 1-10mL test solution in 100mL volumetric flask, with distilled water diluting, to scale, shake up.Do reagent blank simultaneously.

3. the test of experimental result

Press the Instrument working parameter of table 2, standard series, reagent blank, sample solution are introduced respectively to ICP-MS and measure, by workstation software, analyze data, drawing standard curve, calculation sample content.

Table 2ICP-MS instrument condition of work and data acquisition parameters

4. the calculating of experimental result

$\mathrm{\&omega;}\left(K_{2}O\right)=\frac{C\&times;{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="DEST\_PATH\_HSB00001083919100011.png"\; state="\{\{state\}\}">V</figure-callout>}}_1\&times;V_2}{m\&times;V\&times;{10}^9}\&times;100\&times;1.2051$

ω (K ₂o)---potassium is (with K ₂o meter) content (%);

C---potassium element measured value, (μ g/L);

V---draw the volume (mL) of digestive juice;

V ₁---the volume of constant volume (mL) for the first time;

V ₂---the volume of constant volume (mL) for the second time;

M---sample quality (g).

Two, experiment show discussion

Below in conjunction with concrete enforcement example, the present invention is further detailed explanation.

1. the drafting of typical curve (seeing Figure of description 1)

2. pair humic acid sample has carried out 8 parallel experiments, and test result sees the following form 3.

Table 3

3. with the test result comparison of chemical method

Get respectively four kinds of humic acids and the pure potassium dihydrogen phosphate reagent of top grade of different content and composition, measure respectively the content of potassium by traditional gravimetric method and ICP-MS method, test result sees the following form.

Table 4 potassium is (with K ₂o meter) content (%)

Sample classification	Gravimetric method	ICP-MS method	Absolute difference
				Humic acid 1	10.38	10.49	0.11
Humic acid 2	10.06	10.17	0.11
				Humic acid 3	10.44	10.60	0.16

[0044]?

Humic acid 4	11.56	11.72	0.16
				Potassium dihydrogen phosphate	34.19	34.42	0.23

4. take sample 1.0g, add the potassium standard solution of different amounts, according to sample treatment, make solution to be measured, and test, the results are shown in Table 5.

Table 5: sample recovery rate is tested (with K ₂o meter) content (%)

By table 3, table 4, table 5, can be found out, this method has good preci-sion and accuracy, and the absolute difference of test findings gained all meets the regulation of GB standard.

Claims (1)

1. (1) accurately takes sample 0.5g (being accurate to 0.0001g) and is placed in digestion tube, adds 10mL red fuming nitric acid (RFNA), puts into microwave dissolver and digests, and clears up program in Table 1.Be cooled to after room temperature, with ultrapure water, be transferred to the volumetric flask of 100ml, constant volume, standby.Shake up standbyly, do reagent blank simultaneously.

The program design of table 1 microwave digestion

Divide and get 1-10mL test solution in 100mL volumetric flask, with distilled water diluting, to scale, shake up.Do reagent blank simultaneously.

(2) test of experimental result:

Press the Instrument working parameter of table 2, standard series, reagent blank, sample solution are introduced respectively to ICP-MS and measure, by workstation software, analyze data, drawing standard curve, calculation sample content.

Table 2ICP-MS instrument condition of work and data acquisition parameters

(3) calculating of experimental result:

$\mathrm{\&omega;}\left(K_{2}O\right)=\frac{C\&times;V_1\&times;V_2}{m\&times;V\&times;{10}^9}\&times;100\&times;1.2051$

ω (K ₂o)---potassium is (with K ₂o meter) content (%);

C---potassium element measured value, (μ g/L);

V---draw the volume (mL) of digestive juice;

V ₁---the volume of constant volume (mL) for the first time;

V ₂---the volume of constant volume (mL) for the second time;

M---sample quality (g).

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