Metal Element<doubaocanvas> elements are widely present in nature, industrial products, biological tissues, and environmental media. The level of their content directly affects material performance, product quality, ecological security, and human health. Accurate determination of metal element content is a core link in industrial quality control, environmental monitoring, food safety, and life science research, providing key data support for decision-making in various fields.

Shanghai Jituo Technology provides metal element analysis and testing services such as ICP, ICP-MS, IC, XRF, XPS.

1. Multi-Dimensional Testing Methods

- 1.1 Atomic Spectroscopy Analysis

Atomic spectroscopy analysis is a mainstream technology for quantitative analysis of metal elements, divided into Atomic Absorption Spectroscopy (AAS) and Atomic Emission Spectroscopy (AES).

• AAS Principle & Features: Based on the absorption of light of a specific wavelength by gaseous metal atoms. The absorbance and concentration follow the Lambert-Beer Law. It has:
  • High sensitivity (detection limit up to μg/L level)
  • Good selectivity (minimizes interference from coexisting elements)
  • Limitation: Only analyzes one element at a time
• AAS Application: Accurate quantification of lead/cadmium in food, copper/zinc in water quality.
• AES Principle & Features: Excites metal atoms to an excited state via high temperature; atoms emit characteristic spectra when transitioning back to the ground state. Concentration is determined by spectral line intensity. It has:
  • Multi-element simultaneous analysis (e.g., 10+ elements in alloys)
  • Fast analysis speed
  • Limitation: Slightly lower sensitivity than AAS
• AES Application: Batch screening of multi-metal elements in industrial raw materials.

1.2 X-Ray Fluorescence Spectroscopy (XRF)

1.2.1 Principle

Uses X-rays to irradiate samples, exciting inner-shell electron transitions. Outer-shell electrons emit characteristic fluorescent X-rays when filling vacancies; elements are identified/quantified via fluorescent wavelength and intensity.

1.2.2 Core Features

• Non-destructive testing (no sample damage)
• Rapid analysis (completed within minutes)
• Wide detectable element range (light metals to heavy metals)
• Limitation: Accuracy affected by matrix effect

1.2.3 Application

• Rapid screening of metal material components (e.g., alloy grade identification)
• Preliminary determination of total metal content in ores (serves as "pre-analysis" before precise testing)

1.3 Spark Direct Reading Spectroscopy

1.3.1 Principle

Uses high-frequency arc/spark to excite solid metal samples (e.g., steel, aluminum alloys), vaporizing samples to generate plasma. Spectrometer detects characteristic spectra emitted by plasma, directly reading element concentration.

1.3.2 Core Advantages

• In-situ analysis (no sample digestion required)
• High accuracy (relative error < 1%)
• Multi-element simultaneous determination (20+ elements at once)

1.3.3 Application

"Quality control tool" in industrial metallurgy: Real-time monitoring of component content in steel/non-ferrous metal alloy production, ensuring compliance with grade standards.

1.4 Chemical Analysis Method

Based on chemical reactions, divided into Gravimetric Analysis and Volumetric Analysis (Titration).

1.4.1 Gravimetric Analysis

• Principle: Converts target metal elements into weighable compounds via precipitation/volatilization; calculates content from compound mass.
• Features:
  • Ultra-high accuracy (relative error < 0.1%)
  • Limitation: Cumbersome operation, time-consuming
• Application: Precise determination of major metal elements (e.g., high-content iron/copper in ores)

1.4.2 Volumetric Analysis (Titration)

• Principle: Uses quantitative reaction between standard solution and target metal ions; calculates concentration via volume of standard solution consumed at titration endpoint.
• Features:
  • Easy operation, low cost
• Application: Routine analysis of major metal ions (e.g., calcium/magnesium in water, nickel in electroplating solutions)

1.5 Ion Chromatography (IC Method)

1.5.1 Principle

A branch of liquid chromatography: Uses ion exchange resin to separate metal ions (via differential adsorption-desorption capacity); eluent elutes ions, detected by conductivity/UV detector. Qualification via retention time, quantification via peak area.

1.5.2 Core Advantages

• Excels at analyzing water-soluble metal ions (e.g., Na⁺, K⁺, Ca²⁺, Mg²⁺) and low-valence metal ions (e.g., Fe²⁺, Cu⁺)
• Detection limit up to μg/L level
• Multi-ion simultaneous separation (e.g., anions/cations in drinking water)
• No sample atomization required; low matrix requirement (e.g., no dilution for high-salt samples)

1.5.3 Application

• Determination of potassium ion in potassium sorbate (mineral water)
• Monitoring of Na⁺, Cl⁻, and heavy metal ions (e.g., Ni²⁺) in electronic industry cleaning waste liquid (ensures wastewater discharge compliance)

1.6 X-Ray Photoelectron Spectroscopy (XPS)

1.6.1 Principle

Uses monochromatic X-rays to irradiate sample surfaces, exciting inner-shell electrons (photoelectrons). Calculates binding energy** via Einstein’s equation:
Elements are qualified via characteristic binding energy; semi-quantified via photoelectron peak intensity (peak area) + sensitivity factor. Also analyzes **chemical valence state (e.g., binding energy difference between Fe²⁺ and Fe³⁺).

1.6.2 Core Features

• Surface analysis technology (analysis depth: 1-10 nm)
• Capabilities: Element qualification, semi-quantification, valence state analysis
• Limitation: No precise major-element quantification (relative error: 5%-10%)

1.6.3 Application

• Study of metal element composition/valence changes on material surfaces (e.g., metal element distribution on coatings, valence analysis of metal corrosion products)
• Detection of low-content/surface-enriched metal elements (e.g., Cr³⁺ in stainless steel passive film for corrosion resistance evaluation; surface purity/oxidation state of Au/Ag electrodes in semiconductor chips)

1.7 Spectrophotometry

• Principle: Uses formation of colored complexes between metal ions and chromogenic agents; quantifies via absorbance measurement of complexes.
• Features: Easy operation, low cost
• Application: Routine detection of major metal ions (e.g., iron/manganese in water) in primary laboratories

2. Overview of Multiple Application Fields

2.1 Industrial Manufacturing Field

2.2 Environmental Monitoring Field

2.2.1 Water Quality Monitoring

• IC Method: Determine Ca²⁺/Mg²⁺ in surface water (evaluate water hardness)
• AAS: Detect Pb/Hg/As in drinking water (complies with GB 5749-2022 Sanitary Standard for Drinking Water)
• XRF: Rapid screening of total heavy metals in industrial wastewater

2.2.2 Soil & Sediment Analysis

1. XRF: Preliminary determination of total heavy metals (Cd, Hg, Cr, Pb) in soil
2. AAS/ICP-MS: Precise quantification to evaluate pollution level (guides safe use of cultivated land)

2.2.3 Atmospheric Monitoring

• Collect PM2.5 particles; use XPS to analyze surface metal elements (e.g., Pb, Zn, Cu) and their valence states
• Trace pollution sources (e.g., industrial emissions, vehicle exhaust)

2.3 Food Safety Field

2.3.1 Food Raw Material Testing

• AAS: Determine cadmium in rice (prevent "cadmium rice" from entering market)
• IC Method: Analyze nitrates/nitrites in fruits/vegetables (prevent poisoning from excessive nitrites)

2.3.2 Processed Food Quality Control

• XPS: Detect metal coatings (e.g., Sn) on food packaging (e.g., tinplate) to prevent coating peeling contamination
• Spectrophotometry: Determine Fe content in canned food (prevent Fe exceeding standards from metal container corrosion)

2.4 Medical & Life Science Field

• Clinical Diagnosis:
  • AAS: Determine blood lead content (diagnose childhood lead poisoning)
  • IC Method: Analyze urine Ca²⁺/Mg²⁺ (assist in osteoporosis diagnosis)
• Biomaterial Research:
  • XPS: Analyze element composition/valence state on medical metal implants (e.g., titanium alloy artificial joints) to evaluate biocompatibility (ensure stable surface oxide layer, avoid immune reactions)

3. Cutting-Edge Prospects and Technological Innovation

With increasing demands for metal element analysis (higher sensitivity, shorter time, better complex matrix adaptability), technologies continue to innovate:

3.1 IC Method Upgrade

• Development of high-efficiency ion exchange resins and hyphenated technologies (e.g., IC-MS)
• Capabilities:
  • Analyze common metal ions
  • Achieve precise determination of ultra-trace heavy metal ions (ng/L level)
• Application Expansion: Complex samples (e.g., seawater, biological fluids)

3.2 XPS Breakthrough

• Nano-scale XPS (higher spatial resolution): Enables micro-area distribution analysis of surface elements
• Combination with in-situ characterization technologies (e.g., in-situ heating, in-situ corrosion): Dynamically observes metal element valence changes
• Value: Provides detailed data for material corrosion mechanisms and catalytic reaction research

3.3 Multi-Technology Hyphenation

Typical combination:
XRF (Rapid Screening) + AAS/ICP-MS (Precise Quantification) + XPS (Surface Valence Analysis)

• Realizes full-dimensional analysis (total amount → trace amount → surface state)
• Application: Complex scenarios (e.g., research on metal element migration/transformation in soil-plant systems)

4. Microscopic Power Creates Macroscopic Value

Metal element testing methods have continuously broken technical boundaries:
From traditional chemical analysis → modern instrumental analysis; From total amount determination → surface valence analysis.
The addition of IC and XPS has enriched analysis tools:

• IC Method: Efficient solution for water-soluble metal ion analysis
• XPS: New perspective for studying surface metal elements
  In the future, with the development of intelligent technologies (e.g., fully automatic sample pretreatment, AI data analysis) and miniaturization technologies (e.g., portable XRF, handheld IC detectors), metal element testing will become more convenient, accurate, and accessible—continuously contributing microscopic power to ecological security, human health protection, and industrial upgrading.