foster + freeman

Description

ECCO is a new turnkey system from Foster + Freeman designed to give elemental analysis of  trace evidence such as glass, metals, paint, fibres, tapes, minerals and fillers, etc. as well as fast processing of gunshot residues by laser induced breakdown spectroscopy (LIBS).

LIBS is a relatively new technique for elemental analysis which offers significant advantages in speed, sensitivity and cost effectiveness over other processes such as XRF, SEM, and mass spectroscopy.  It uses a  high intensity pulsed laser focussed on the sample to create a tiny plasma of  vaporised matter which emits an atomic spectrum of the constituent elements of the sample - a material "fingerprint" .

Elemental comparisons with ECCO are fast and simple to perform, require minimal sample preparation and give immediate  read out of the major, minor and trace elements down to concentrations of low parts per million.

Applications

To view the available Application Notes click on the links below:

Application Note: Discrimination of glasses of the same RI

One of the most widely applied techniques for the forensic analysis of glass involves the measurement of its refractive index (RI) using the oil immersion method. The Foster + Freeman GRIM system is a compact and convenient instrument intended for this purpose and has been used by all major forensic science laboratories for over twenty years. Improvements in glass manufacturing processes, however, have caused the variation in RI to be significantly reduced and it is now often necessary to subject glass evidence to additional examination by elemental analysis.
In this Application Note, we demonstrate the potential of the ECCO to differentiate between glass samples which cannot be distinguished by the measurement of RI alone.

Application Note: Determination of glass type using LIBs

It is generally useful to be able to identify the type of glass in the fragments recovered from a scene of crime. Whilst the measurement of RI is an extremely discriminatory technique, this alone cannot always conclusively determine the glass type: float and container glass, for example, exhibit distributions of RI which overlap in value even though the elemental compositions of these glass types are often quite different. Similarly, whilst a borosilicate glass, such as Pyrex, can be distinguished from float or container glasses by its refractive index, in practice, the difference in RI is so significant that the GRIM system must be laboriously recalibrated each time the type of glass is changed. Other elemental analysis techniques such as SEM-EDX and XRF are also blind to low atomic number elements, such as boron, the detection of which would confirm a glass as of the borosilicate type.

Application Note: Security Documents

The most commonly applied method for the forensic examination of paper involves close visual inspection, possibly aided by the wide spectral range of the UV, IR and visible light sources in instruments such as the Foster + Freeman Video Spectral Comparator.
Recent studies have been reported, however, in which paper has been examined using elemental analysis techniques. These studies have measured trace elements such as barium and strontium, which occur as impurities in the calcium carbonate and other fillers used in the papers manufacture. Security papers, however, tend to have a quite different composition to normal types of paper and are often devoid of optical brighteners. Instead, uncommon elements, such as manganese or titanium, may be present, either having been added intentionally or occurring incidentally as a constituent of colourants.
This Application Note shows the different elemental profiles of three different types of security paper.

Application Note: Identifying Fake Coins

The number of counterfeit £1 coins in circulation in the UK has risen steadily over the last few years, probably because of the ease with which coins can now be counterfeited compared with paper banknotes. Whilst close visual inspection (inconsistencies in the date and design, poor quality of less prominent features, incorrect dimensional tolerances) can often be used to identify counterfeit coins, such methods are not entirely reliable.
Recent studies have been reported, however, in which counterfeit coins can be detected by elemental analysis. The presence or absence of specific trace elements can often distinguish genuine coins from counterfeit.

Application Note: Gunshot Residue (GSR) Screening

A recent study of GSR screening methods by the Centre for Material Science and Engineering at Cranfield University, UK has shown that that the Foster + Freeman ECCO can provide forensic examiners with a high-speed and consistently accurate solution, particularly when large numbers of samples are submitted for analysis.
Using Laser Induced Breakdown Spectroscopy (LIBS) the ECCO has been used to rapidly screen swabs from suspects’ hands for elements consistent with GSR, such as the detection of Barium (Ba) and Lead (Pb). Once a screened sample has tested positive for GSR it may then undergo lengthier and more detailed analysis if required.

Features

• Automatic identification of elements with measurement of elemental ratios and concentrations.
• Routine and research  modes of operation.
• Detects most elements encountered in particulate trace evidence.
• Integral colour camera for sample selection.
• XYZ sample positioning/focusing stage.
• Air Cooled Q-switched 1064nm Nd:YAG laser.
• Full laser safety features.
• Miniature footprint.
• Dedicated software module for the routine analysis of evidence types.