Sequential Scanning ICP-OES Spectrometer

What is the Sequential Scanning ICP-OES Spectrometer?

A sequential scanning ICP-OES spectrometer measures one wavelength at a time with a movable grating. It is chosen for flexible, lower-cost laboratories that need many analytical lines but fewer routine samples per hour.

Overview

In a sequential instrument a scanning monochromator or a movable optics assembly selects the wavelength of interest, and the detector measures one line at a time. This allows a very wide wavelength range, including far-ultraviolet lines, and easy access to alternative lines for interference checks, because the wavelength can be programmed for every element in the method. Peak height and profile are measured as the grating scans, so wavelength accuracy can be verified from the peak itself. The trade-off is longer analysis time, typically tens of seconds to minutes per sample depending on the element list, and slightly lower precision than simultaneous systems. Sequential instruments are often smaller and less expensive, and they suit method development, research and laboratories with moderate sample numbers and changing element lists.

How does it work?

A radio-frequency generator drives a load coil around a quartz torch, sustaining an argon plasma at 6000 to 10000 K. The sample aerosol enters the plasma and is desolvated, vaporized, atomized and excited. Excited atoms and ions relax and emit light at wavelengths characteristic of each element. The emitted light is dispersed by an echelle grating or a CCD-based polychromator, and multiple lines are measured simultaneously. In radial viewing the plasma is observed from the side, which tolerates high dissolved solids and reduces self-absorption; in axial viewing the plasma is observed end-on, which lengthens the optical path and lowers detection limits. Dual-view instruments switch per element. Internal standards, background correction and interference algorithms correct for drift and overlapping lines. The wide dynamic range lets major, minor and trace elements be measured in one run.

What are the key features?

• Scanning monochromator with movable grating
• Wide wavelength range including far ultraviolet
• Easy access to alternative lines for interference checks
• Peak profile and wavelength verification from scans
• Lower cost and smaller footprint
• Suited to changing element lists and method development

What are the technical specifications?

A typical sequential scanning icp-oes spectrometer configuration offers wavelength range of 160–900 nm, monochromator of scanning grating, optical resolution of ≤ 0.01 nm at 200 nm, detection limit of 1–20 µg/L typical, analysis time of 30–180 s per sample and detector of photomultiplier. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Sequential Scanning ICP-OES Spectrometer is used in method development and research, laboratories with changing element lists, educational and small analytical facilities and interference investigation and line selection. Across the wider ICP-OES class, laboratories also deploy it for multi-element water and wastewater analysis, pharmaceutical elemental impurity screening and food, feed and agricultural element analysis.

Which standards and certifications apply?

Relevant standards and methods include USP <730> Plasma Spectrochemistry, USP <233> Elemental Impurities — Procedures, ICH Q3D Elemental Impurities, ISO 11885 Water quality — ICP-OES determination of elements, US EPA Method 200.7, ASTM D5185 and ISO/IEC 17025. Certification candidates for this model are CE, ISO 9001 manufacturing and IEC 61010-1 safety compliance; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

ICP-OES requires high-purity argon, substantial power, exhaust ventilation and a temperature-controlled room. Torch, injector and nebulizer condition strongly affect performance, so inspection and replacement schedules are important. High dissolved solids cause salt build-up on the torch and injector, blocking the plasma and changing sensitivity, so dilution and matrix matching are used. Sample preparation by acid digestion must avoid contamination. Daily checks include wavelength calibration, torch alignment, plasma stability and a check standard. Monitor the argon supply and the chiller, and record torch and nebulizer usage. Data integrity requires calibration verification, QC samples and defined acceptance criteria.

How do I select the right Sequential Scanning ICP-OES Spectrometer?

Select a sequential instrument when flexibility and cost matter more than throughput, when the element list changes frequently, or when method development requires access to many lines. Specify the elements and expected sample numbers. If sample throughput becomes the bottleneck, a simultaneous instrument is the better long-term choice.

How does it compare with other ICP-OES variants?

Select an ICP-OES spectrometer by viewing configuration, detector type, resolution and automation. Radial viewing is the best choice for high-matrix samples and major elements, axial viewing for the lowest detection limits in clean samples, and dual view for laboratories that handle both. Simultaneous CCD instruments measure many elements and lines quickly, while sequential scanning instruments are flexible and lower in cost but slower. High-resolution echelle optics help when many emission lines overlap, as in rare-earth or iron-rich samples. Confirm the wavelength range covers the elements and lines you need, including far-ultraviolet lines for halogens. Check argon and power consumption, sample introduction options, autosampler capacity and software features such as interference correction and audit trails.