Brookhaven offers a comprehensive range of certified particle size standards used for calibration microscopy, particle size analysis, and contamination monitoring
The certified particle size standards consist of highly uniform polymer, glass, or silica microspheres with mean diameters in the range 20nm to 2000µm.
Each standard is supplied with a certificate of analysis stating the mean diameter, traceable to NIST standards.
Their spherical nature ensures that shape factors do not influence the response of the wide variety of equipment with which they are used and also makes them easily identifiable among other types of particles in direct imaging methods.
The range now includes polymer microspheres of 9µm and 40µm which have specific application as reference standards for certain laser diffraction particle sizers.
A line of dry polymer microspheres with mean sizes from 5µm to 100µm are ideal when aqueous suspensions are not appropriate for the application.
For calibrating air and liquid particle counters with respect not only to particle size but also concentration, the Ezy-Cal series of microspheres with narrowly distributed diameters from 2 to 70 microns is available at fixed and certified concentration of 2000 counts per millilitre.
For parenteral drug manufacturers requiring interim verification of particle counter performance according to USP23, a 15 micron size standard packaged at the required concentration offers an economical alternative to the prescribed USP standard material.
Named Pharm-Trol, this standard is supplied in packs of six or twenty bottles containing 25ml of the aqueous suspension.
In addition to the range of particle size standards, fluorescent particles are also available.
The mean size of the particles is accurately defined and the distribution of diameters is extremely narrow, again facilitating their visual identification.
Particle mean diameters range from 0.025 to 10µm and they are available with three different fluorescent dyes - red, green and blue - incorporated directly into the polymer matrix.
A range of green fluorescent particles with mean diameters from 6µm up to 165µm is also offered as dry powders. Fluorescent or plain microspheres with carefully controlled surface chemistries, designed for covalently or physically attaching biological molecules, have also recently been added to the range.
Surface functionality includes carboxyl, sulphate and aldehyde modifications and most of these new products are supplied in surfactant-free form.
All products are manufactured by Duke Scientific Corporation, USA, for whom Brookhaven is the authorised distributor in the UK and Ireland.
