Full spectrum ICP mass spectrometry (usually referred to as time-of-flight inductively coupled plasma mass spectrometry, TOF-ICP-MS) is a high-throughput elemental analysis technique based on a time-of-flight mass analyzer, which can achieve instantaneous synchronous detection of isotopes across the entire mass range. Compared to traditional quadrupole ICP-MS, full spectrum technology exhibits significant advantages in rapid multi-element analysis, transient signal processing, and isotope ratio determination.
1、 Working principle
1. Ionization and Transport
The sample enters the high-temperature plasma (~800K) through the atomizer, and after ionization, it is extracted to the vacuum system through the interface cone (Sampler/Skimmer Cone).
2. Quality Separation and Testing
Time of Flight Mass Analyzer (TOF): Ions enter the field free drift tube with the same kinetic energy after being accelerated by an electric field. Ions with smaller mass have shorter flight time, while those with larger mass have longer flight time. Mass separation is achieved by detecting differences in flight time.
Full spectrum synchronous acquisition: A single pulse (μ s level) can capture ion signals of the entire mass range (such as Li~U), avoiding time delay in quadrupole scanning.
3. Data processing
By using a high-speed digital converter (ADC) to record the arrival time of all ions, and combining it with a calibration curve to convert the time into a mass to charge ratio (m/z), a complete mass spectrum is generated.
2、 Core performance advantages
| Parameters | TOF-ICP-MS | Quadrupole ICP-MS |
| Detection mode | Full spectrum synchronous detection (simultaneous acquisition of all m/z) | Sequential scanning (point by point measurement) |
| Analysis speed | More than 50000 spectrograms per second | 10-20 mass numbers per second |
| Dynamic range | 10 ⁶ -10 ⁸ (single pulse) | 10 ⁶ (requires segmented scanning) |
| Isotope ratio accuracy | ≤ 0.1% RSD (short-term) | ≤ 0.3% RSD (limited by scanning speed) |
| Transient signal analysis | Support single pulse (such as laser ablation, single particle analysis) | Multiple scans are required, which may result in loss of signal details |
3、 Typical application scenarios
1. Multi element rapid analysis
Environmental monitoring: Simultaneous detection of trace heavy metals (As, Cd, Hg, etc.) in water and soil, with a single injection completing 30+element analysis.
Biomedical: High throughput screening of essential/toxic elements (Fe, Zn, Pb) in serum and tissues.
2. Transient signal analysis
Laser ablation (LA): Imaging of element distribution in mineral micro regions with spatial resolution<10 μ m.
Single particle ICP-MS (spICP-MS): Determination of the number concentration and particle size distribution of nanoparticles (Ag, TiO ₂).
3. Isotope ratio analysis
Geochronology: U-Pb and Sr Nd isotope ratio determination, with accuracy comparable to multi receiver ICP-MS (MC-ICP-MS).
Food safety traceability: lead and strontium isotope fingerprint tracking of wine and coffee production areas.
4、 Instrument structure composition
| Module | Functions and Key Technologies |
| Sample injection system | High precision atomizer, swirl chamber, HF acid resistant (optional) |
| Ion source | Self exciting RF generator, power 1.2-1.6kW, equipped with a three cone interface to reduce background noise |
| Quality analyzer | Orthogonal acceleration TOF, mass resolution>6000 |
| Detector | Dual mode detector (analog/counting mode), with a dynamic range coverage of 1-10 ⁸ cps |
| Data processing | Real time deconvolution algorithm to eliminate quality interference (such as the impact of ⁴⁰ Ar ³ ⁵ Cl on 𔑃⁵ As) |