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Model 420 and 425 Dual Channel Flame Photometer

Sherwood Flame Photometers

Sherwood Scientific offer a range of flame photometers for the determination of the alkali and alkaline earth metals. They offer simple and fast analysis for a wide range of sample types such as:

  • Biological samples
  • Food and beverages,
  • Cement, gypsum and plasterboard manufacture
  • Fertiliser, feed and soil
  • Chemicals
  • Environmental

Product Overview

Sherwood Flame Photometers can be used to determine Sodium, Potassium, Lithium, Calcium, Barium, Strontium, Rubidium and Caesium in a variety of sample types. Some common applications are listed below:

Sodium, Potassium and Lithium in Body Fluids – One of the most important applications is in the clinical chemistry field as it provides a rapid and reliable means of estimating sodium, potassium and lithium in body fluids such as serum and urine.

Sodium and Potassium in Cement – Another widely used application is soda and potash in cement. The addition of aluminium nitrate solution suppresses the interference caused by concentrations of lime.

Calcium in Beer – The determination of calcium in beer may be carried out by preliminary separation of calcium as oxalate followed by the addition of perchloric acid, which releases the calcium from the inhibiting effect of the oxalate.

Potassium in Fertilisers and plant material and soils

Sometimes the samples can simply be diluted prior to determination, other times they need some sample preparation such as ashing or digestion. Sherwood have a booklet of applications with written methods available for customers.

All of the models can be enhanced with the addition of the M806 Dilutor for increased accuracy and repeatability. Some models can also use the M865 Autosampler to reduce operator time.

BlueNotes Software is available for most models allowing results to be stored and multi-level calibrations to be performed. There is also a regulated version for laboratories which require IQ/OQ and 21 CFR Part 11.

Features & Benefits

Model 420 and 425 Dual Channel Flame Photometer

Dual Analysis

Sodium and Potassium Measurement


Continuous or Peak Mode

Industrial and Clinical

Model 420 and 425 Options

Key applications of Model 420 and 425

  • Easy to Use
  • Can be used for difficult matrices
  • Low running costs
  • Small footprint
  • Can be used with Sherwood BlueNotes software for complete data traceability
  • Can be automated with the Sherwood Autodilutor and Autosampler

Model 360 Flame Photometer

  • Features: Single channel, auto ignition, flame optimisation, easy cleaning, selected filter indicator, and high sensitivity.
  • Elements: Na, K, Li, Ca, Ba.
  • Versions: Available in 3 versions, including a clinical version.
  • Ideal For: Basic yet robust elemental analysis.
Model 360 Flame Photometer

Model 410 Flame Photometer Series

  • Features: Preloaded filter stick (up to 3 elements), front panel LED for air supply indication, no tools required for filter change.
  • Models:
    • M410 Classic: Includes sodium, potassium, and calcium filters; serial and USB connectivity; no printer connectivity.
    • M410 Industrial: additionally has Sodium linearisation (up to 50ppm), NIST traceable standards available, designed for industrial applications.
    • M410 Scientific: Tailored for biological samples like serum and urine, includes Na, K, Li filters, and a multi-element calibrator. Includes Sodium linearisation.
  • Connectivity: Serial printer, USB B for PC connection, USB A for firmware updates.
  • Software Compatibility: BlueNotes 410 for Industrial and Scientific models: data collection, manipulation, and report generation.
  • Automation: The M410 Industrial and M410 Scientific Flame Photometerscan both be used with the Sherwood’s M806 Continuous Flow Diluter and M865 Autosampler for unattended sample analysis .

Model 420 Dual Channel Flame Photometer

  • Features: Dual channel for simultaneous Na and K measurement, auto flame optimisation, internal standard referencing, on-board firmware.
  • Performance: Enhanced sample throughput and precision, automatic ignition, Lithium Internal Reference for analytical performance improvement.
  • Models: Industrial and Scientific, both designed for dual-element analysis.
  • Software: BlueNotes 420 included, offering advanced data handling and reporting capabilities. IQ/OQ also available with the Regulated version.
  • Connectivity: RS232 output for a printer or PC connection
  • Automation: The M420 can be used with the Sherwood’s M806 Continuous Flow Diluter and M865 Autosampler for unattended sample analysis.
MODEL 425 Dual Channel Flame Photometer

Model 425 Dual Channel Flame Photometer

  • Features: Additional detector and filter for Calcium determination, Lithium internal reference, “301 mode” feature which allows connection to some of the more popular continuous flow systems.
  • Performance: High sensitivity and reproducibility, with less than 1% interference in samples containing equal concentrations of Sodium and Calcium.
  • Safety Features: Optical flame and low air pressure detection for fuel gas shut-off.
  • Automation: Works with M865 Autosampler and M806 Continuous Flow Dilutor for unattended sample analysis.

Additional Equipment

  • M806 Dilutor: Ensures consistent dilution ratios, designed for use with M420 or M425 for optimal internal reference material addition.
  • M865 Autosampler: 40 sample capacity, compatible with all Sherwood Flame Photometers, enhances flexibility and operation robustness.
  • Air Compressors (M851 and M855): Essential for stable flame conditions and constant sample delivery, available for humid atmospheres.

Software Solutions

  • BlueNotes Software: Simplifies data collection, storage, and report generation. Features multipoint calibrations, calibration curve saving, and automated analysis with autosampler integration.
  • Regulated BlueNotes 420 Software: Offers a 3-tier login system, audit trail, tamper-evident data files, and auto-generated PDF reports for regulatory compliance.

"The Model 425 Flame Photometer enhances the Model 420 with Calcium
detection and compatibility with continuous flow systems"

Product FAQ's

Flame Photometry is used for Group I and II elements, also referred to as the alkali and alkaline earth metals. Sodium and potassium are the metals most often analysed but the full range is: Sodium, Potassium, Lithium, Calcium, Barium, Strontium, Rubidium and Caesium. Li and Cs are often used as internal reference standards.

Some of the Sherwood Flame Photometers can also use the M865 40 place autosampler.

BlueNotes software can be used with the M410, M420 and M425 Flame Photometers.

The Sherwood Flame Photometers can run with propane or butane and also require compressed air. Some models can also use natural gas.


Application Note 1

Application Note 2

Application Note 3

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