Analysis & Monitoring
Spectrophotometers, chromatography systems, mass spectrometers and elemental analysers for composition and structure.
Analytical instruments determine what a sample contains and in what quantity. They are laboratory instruments by definition, because a sample is taken, prepared and measured under controlled conditions - which is what distinguishes them from the online analysers that work directly on a process stream, and the two are specified in completely different conversations.
Because these systems are normally bought against a documented method, the specification starts with three things and works outwards: the analyte, meaning the substance to be measured; the matrix, meaning everything else in the sample; and the detection limit the result has to reach. Only once those are fixed does the question of which technique and which configuration follow.
That order matters because the same substance can be measured by several techniques with very different running costs, and choosing by technique rather than by requirement is how a laboratory ends up with an instrument it cannot use for the method it has to follow. The supporting environment - gases, vacuum, cooling, consumables and reference standards - is part of the decision rather than an afterthought.
| Product type | How it measures | Usually specified for |
|---|---|---|
| UV-Vis spectrophotometer | Absorption of light at defined wavelengths, converted to concentration through a calibration curve | Quantitative measurement of species that absorb in the ultraviolet or visible range, and routine methods built on colour-forming reactions |
| FTIR spectrometer | Absorption of infrared energy by molecular bonds, compared against reference spectra | Identification of materials and functional groups, including solids and formulations where a quantitative method is not required |
| Gas chromatograph | Components are separated in a carrier gas stream and detected as they elute | Volatile and semi-volatile mixtures, residual solvents, and purity checks where a separation is required before identification |
| Liquid chromatograph | Components are separated in a liquid mobile phase across a stationary phase | Non-volatile, thermally labile and ionic compounds that would not survive a gas chromatographic method |
| Mass spectrometer | Ions are separated by mass-to-charge ratio and detected, giving high specificity | Confirmation and identification where a low detection limit and an unambiguous answer are both required |
| Atomic absorption spectrometer | Ground-state atoms absorb light at element-specific wavelengths | Metal concentrations in water, soils, alloys and biological samples, where one element is determined at a time |
| TOC analyser | Organic carbon is oxidised and the resulting carbon dioxide is measured | Water and wastewater work where organic loading is the reported figure, and where a regulatory limit applies |
| Particle size analyser | Laser diffraction or image analysis derives a size distribution from the sample | Powders, suspensions and emulsions, where the distribution rather than a single value is the result |
Colorimeters, elemental analysers and the accessories that support these systems are listed under this category as well.
There is rarely a single correct instrument for a duty, but there is always a shortlist that can be justified and a set of answers that eliminates the rest. These are the questions that decide it.
| Technology | Best suited to | Limits | Typical question |
|---|---|---|---|
| UV-Vis molecular absorption | Quantitative methods built on an absorbing species or a colour-forming reaction | Needs a chromophore, is exposed to matrix interference, and depends on careful cuvette handling and blanking | How much of a known substance is present |
| FTIR spectroscopy | Identifying what a material is, including solids and mixtures | Water and some matrices interfere, and interpreting a complex mixture depends on the reference libraries available | What is this material |
| Gas chromatography | Volatile and semi-volatile mixtures that have to be separated before they are measured | The sample has to be volatile and thermally stable, and column and detector selection decide what can be resolved | Which components are present, and in what proportion |
| Liquid chromatography | Non-volatile, labile and ionic compounds, including large molecules | Solvent consumption and method development time; the mobile phase becomes a running cost and a disposal question | What is the composition of a liquid mixture |
| Atomic absorption | Metal concentrations across a wide range of matrices | The classical arrangement determines one element at a time, and some elements need a different atomisation approach | How much of this metal is present |
| Mass spectrometry | Identification and confirmation at low concentration, alone or as a detector for a separation technique | Needs vacuum, a controlled environment, consumables and skilled interpretation; it is rarely a stand-alone first purchase | Exactly what is present, at very low concentration |
What is left after the technology is chosen is a list of values that only the installation can supply. These are the ones that change the model, the price or the lead time:
Specifications vary by model and application, so no performance figure is stated on this page. Where a parameter has not been documented for a particular model, the product page says so rather than filling the gap with a plausible number. Send the values above and we will return the ones the selected model actually holds.
Frequently asked
The questions that come up before an order rather than after it. If yours is not here, send it with the requirement and we will answer it in the quotation.
Start from the analyte, the matrix and the detection limit, and let the method decide. A single element in water and the same element in a digested solid may need different approaches, and a volatile mixture needs a separation before identification while a pure substance may not. The techniques in this category overlap but are not interchangeable, and choosing by requirement is faster than comparing specifications.
Where and how the sample is handled. A laboratory instrument works on a prepared sample under controlled conditions and is judged on sensitivity and repeatability. An online analyser works on the stream as the process delivers it and is judged on drift and service interval. The same parameter can therefore be measured on both, and the choice depends on whether the answer is needed continuously or on a batch of samples.
Because it decides whether the method can answer the question at all. An instrument that detects a substance but cannot quantify it reliably at the level the result is compared against will produce inconclusive data. It also affects the sample preparation route, since reaching a low limit often requires a concentration step that adds time and error. State the level the result has to be judged against, not just the substance to be detected.
Consumables dominate: columns, lamps, filters, gases, solvents and reference standards all have finite lives, and some are specific to the model. Add the electricity, cooling and vacuum the system needs, plus the service arrangement. A system with a low purchase price and short-lived proprietary consumables can cost more per sample than a more expensive instrument, so it is worth asking about the consumables list before choosing.
Most of them do, and the requirement varies by technique. Gas supply, vacuum, cooling water, ventilation and temperature stability all appear, and the bench footprint is rarely the real constraint. A mass spectrometer in particular needs a stable environment and a vacuum system that is maintained. Confirming what the building can provide is worth doing before the instrument is selected.
What can be supplied is the instrument and its documentation, and where reference materials or standards are needed they should be named in the enquiry so that they can be quoted together with the system. Method development is normally carried out by the laboratory or by the instrument supplier as a service, and it is worth establishing at the enquiry stage which of those routes applies.
Available now
UVS-1900 · Spectrophotometers Reference listing
Double-beam UV-Vis spectrophotometer covering 190 to 1100 nm with a scanning monochromator, for quantitative analysis and wavelength scanning in the laboratory.
Send the specification and we will confirm the matching instrument, availability and lead time. Minimum order quantity is 1 pc.
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Send the technical detail and we will confirm availability, lead time and terms. In-stock items ship within 48 hours; customized specifications typically take 2-10 days. Minimum order quantity is 1 pc.