Method for measuring element content in minerals or soil and sample pretreatment method

Abstract

The invention relates to a method for measuring the element content in minerals or soil and a sample pretreatment method, belonging to the element detection field. The invention relates to a sample pretreatment method for measuring the element content in minerals or soil firstly. The sample pretreatment method comprises the following steps: a. weighing a sample to be detected, adding with hydrofluoric acid until the solution is quiet without air bubbles to obtain a solution A; b. adding hydrochloric acid and nitric acid into the solution A until the solution is quiet without air bubbles to obtain a solution B, wherein the volume ratio of hydrochloric acid to nitric acid is 3:1; c. adding water into the solution B, and carrying out primary microwave digestion reaction in a closed environment; d. heating continuously and carrying out secondary microwave digestion reaction; and e. cooling to obtain the pretreated sample. Furthermore, the invention also discloses a method for measuring the element content in minerals or soil. The method has the advantages of convenience, rapidness, high accuracy and the like.

Description

technical field [0001] The invention relates to a method for measuring element content in minerals or soil and a sample pretreatment method thereof, belonging to the field of element detection. Background technique [0002] By accurately measuring the contents of heavy metal elements such as mercury, lead, arsenic, antimony, etc., precious metal elements such as silver, and other beneficial metal elements such as iron, copper, chromium, manganese, and nickel contained in polymetallic gold minerals or soil samples in a certain geographical area, it can be grasped Chemical properties such as the chemical element composition and content levels of the regional soil, especially the basic geographical information such as toxic and harmful heavy metal elements and their content in the soil, or grasp the metallogenic laws, ore-controlling conditions, and mineral resources of the corresponding metals in mineral resources. Types of mineralization, etc., so as to lay the foundation for...

AI Technical Summary

Problems solved by technology

For trace or trace levels of heavy metal elements such as mercury, lead, arsenic, antimony, etc., precious metal elements such as silver, and other beneficial metal elements such as iron, copper, chromium, manganese, nickel, etc., ICP-OES, ICP-MS, AAS or , AFS and other instrument detection methods for the determination of element content, but the existing analysis methods mainly have shortcomings such as unsuitable sample digestion and preparation methods

Since the elements to be measured, such as mercury and arsenic, are extremely volatile and lost, the traditional wet or fire digestion methods in the open state will seriously affect the accuracy of the measurement results due to the volatilization of mercury during the preparation of the test sample solution or solid. property; although conventional microwave or high-pressure ax digestion methods in a closed state can avoid the loss of volatile elements such as mercury, but due to the limitation of the element detection ability of the detection instrument, in order to ensure the effective determination of trace or trace amounts in the sample For metal elements, measures such as increasing the weight of the sample and reducing the dilution ratio can only be taken. By artificially increasing the concentration of the element to be measured in the prepared sample solution to ensure that it is greater than the lower limit of detection of the instrument, the trace or trace level of the sample can be guaranteed. The element components can be detected by the instrument, but due to the large amount of silica, aluminum oxide and other components in the matrix coexisting in the prepared sample detection solution, the matrix effect and other interference factors seriously affect the trace or trace. Accurate determination of trace element components, and the salt concentration is much higher than the maximum salt tolerance of 10 mg / mL that can be tolerated by ICP-OES, ICP-MS and other detection instruments (that is, it is usually required to weigh up to 1.0 g After the sample is digested and diluted to a 100mL volumetric flask), the transmission atomization efficiency of the pneumatic nebulizer is greatly reduced, which seriously affects the stability and precision of element determination, and even the "salting out effect" leads to ICP-OES, AAS, The pneumatic nebulizer of ICP-MS and other detection instruments is blocked, or the sampling cone and skimmer cone of the ICP-MS sampling system are blocked by deposition, which makes the detection instrument unable to work normally.

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