Inorganic Pretreatment Room

Date：2025/7/7 17:13:38

Inorganic Pre-treatment Room: Functions, Equipment and Safety Specifications

I. Core Functions

The inorganic pre-treatment room is mainly used for the pre-treatment of inorganic samples (such as metals, ores, water quality, food, etc.). Through operations such as digestion, dissolution, and separation, the samples are converted into solutions or states suitable for instrumental analysis (such as ICP-MS, AAS, XRD, etc.). Common treatments include:

Sample digestion: Using strong acids (such as nitric acid, hydrochloric acid, hydrofluoric acid), high temperature or microwave assistance to destroy the sample matrix and release target inorganic elements (such as heavy metals, trace elements).

Separation and enrichment: Using methods such as precipitation, extraction, and ion exchange to remove interfering substances or concentrate low-concentration target elements.

II. Key Equipment and Consumables

Equipment Type	Uses and Characteristics
Hot plate / Digester	Used for heating samples and acid solutions to achieve wet digestion (e.g., hot plate with temperature control accuracy of ±5℃, microwave digester can achieve rapid digestion under high temperature and pressure).
Fume hood	Made of anti-corrosion materials (such as PP board), equipped with a strong exhaust system to remove acid fumes generated during digestion (wind speed ≥0.5m/s).
Laboratory bench	The 台面 is made of acid and corrosion-resistant materials (such as epoxy resin board), with a water retaining edge at the edge to prevent liquid spillage.
pH meter / Conductivity meter	Used to adjust the pH value of the solution or monitor water quality to ensure accurate sample pre-treatment conditions.
Pipette / Volumetric flask	For accurate measurement of reagents and volume fixing, acid-resistant glass or plastic materials should be used.
Muffle furnace	Used for high-temperature ashing of samples (such as determining the ignition residue of inorganic components), with a temperature up to 1000℃ or higher.

III. Typical Pre-treatment Process

Sample preparation: Crush and sieve solid samples (such as ores), or homogenize liquid samples (such as water samples).

Digestion methods:

Wet digestion: The sample and mixed acid (such as HNO? + HClO?) are heated on a hot plate until clear and transparent, suitable for metals, soil, etc.

Microwave digestion: The sample and acid solution are sealed in a polytetrafluoroethylene tank and heated by microwave for rapid digestion, suitable for trace samples and volatile elements (such as Hg).

Dry ashing: The sample is ashed at high temperature in a muffle furnace, and then the residue is dissolved with acid, suitable for samples with high organic content (such as food).

Purification and volume fixing: Remove impurities by filtration, centrifugation or solid-phase extraction, and fix the volume to the specified volume with ultrapure water.

IV. Safety and Protection Requirements

Hardware protection:

The fume hood needs to regularly check the exhaust efficiency to ensure that acid fumes are discharged in time; the table top and cabinet body need to be acid and corrosion resistant (such as PVC or epoxy resin materials).

Equipped with emergency shower devices and eye washers, which are no more than 15 meters away from the operation area to prevent strong acid splashing.

Operating specifications:

Digestion must be carried out in a fume hood. Strong acids should be added slowly to avoid violent reactions; high-temperature operations (such as muffle furnaces) require wearing heat-insulating gloves.

Waste acid solutions need to be collected separately (such as fluorine-containing waste liquid stored separately), and discharged in accordance with environmental protection standards after neutralization treatment.

Personnel protection:

Wear acid-resistant lab coats, rubber gloves, and goggles to avoid direct contact between the skin and strong acids.

V. Differences from Organic Pre-treatment Room

Comparison Item	Inorganic Pre-treatment Room	Organic Pre-treatment Room
Core reagents	Strong acids (HNO?, HCl, HF), strong bases (NaOH), etc.	Organic solvents (methanol, acetonitrile, n-hexane), etc.
Main risks	Acid mist corrosion, high-temperature burns	Organic vapor poisoning, flammability and explosiveness
Ventilation requirements	Focus on removing acid mist, and the exhaust system needs anti-corrosion	Focus on adsorbing organic vapors, requiring activated carbon filtration devices
Sample processing target	Release inorganic elements and eliminate matrix interference	Extract organic compounds and purify samples

VI. Application Scenarios

Environmental monitoring: Pre-treatment of heavy metals (such as Pb, Cd, Cr) in water quality and soil.

Food testing: Analysis of trace elements (such as Fe, Zn) or harmful metals (such as As, Hg) in milk powder and vegetables.

Material analysis: Determination of element content in metal alloys and ores (such as carbon and sulfur content in steel).

Pharmaceutical testing: Detection of inorganic impurities (such as heavy metal residues) in pharmaceuticals.

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