42 Testing PET Preforms for Consumer Safety
Formaldehyde is a chemical widely used in the industrial production of materials like plastics, for the processing of fabrics or to preserve biological materials. However, formaldehyde is considered by many standards to be a health hazard. It can cause allergic reactions and was
classified as carcinogenic in 2004. According to the German standard Oeko-Tex 100, baby clothes must not contain more than 20 PPM of this substance.
The beverage industry tests plastic bottles for formaldehyde as part of their quality control process. This is usually performed on the preforms for the beverage bottles. Before the actual analysis can be done, the formaldehyde must be extracted from a sample. To do this reproducibly, the sample first has to be comminuted. Because formaldehyde is a volatile substance, the mechanical energy input which is necessary for the grinding process can lead to its evaporation. To avoid this effect, cryogenic grinding is the method of choice.
The first step, however, is the short and gentle preliminary grinding of the preforms in a cutting mill, such as Retsch’s SM 100, with a bottom sieve of 6mm. The obtained granules are then pulverised in the Retsch CryoMill at – 196°C with liquid nitrogen. The cooling ensures that the sample does not warm up during grinding, thus preserving the formaldehyde. Moreover, the sample is embrittled which improves the milling process. The CryoMill quickly grinds the preforms down to a powder of 100 microns and less which can then be used for extraction of the formaldehyde. The actual spectroscopic analysis is carried out by colour reaction (for example, with MBTH or Schiff test). Retsch crushers and mills are ideal tools for representative and reproducible size reduction and homogenisation of solids in the context of quality control.
Circle no. 390 Smooth Operators
Elkay Laboratory Products Ltd now offer an extensive range of low- binding filter pipette tips, from 10µl to 1200µl, with extended lengths and fine-tips.
Contamination resulting from sample adhesion on the tip wall or aerosols generated by pipetting action can adversely affect subsequent reactions and lead to inaccurate results. To reduce the effect of sample binding, Elkay utilise a proprietary bonded polymer that creates a hydrophobic surface that lowers surface tension between the sample and tip material. No additives are used and the polymer is both chemically resistant and inert. This ensures there is no leaching and that samples will not be affected by most common laboratory solvents such as acetone and chloroform.
The inert, hydrophobic filter in each tip reliably prevents both liquid and aerosol contamination of the pipette, while also wicking any sample away from the filter in the case of over-pipetting.
All Elkay filter tips are manufactured from premium-grade virgin polypropylene and are supplied RNase, DNase, DNA and Pyrogen free. This high-quality combination ensures scientists the peace of mind that they are not compromising sample integrity. Free samples are available for evaluation purposes and customers are welcome to discuss their needs with an Elkay sales representative.
Circle no. 391 Joining Forces Across World Markets
Integra Biosciences AG, Switzerland, and Viaflo Corporation, US, have announced that they signed agreements to combine the two companies under the name of Integra Viaflo Holding AG on July 23, 2009. The new group will be active across world markets under the brand ‘Integra’. This move follows the signing of a successful strategic marketing and distribution partnership around one year previously.
The combining of the two companies provides for strong mutual benefits. Integra Biosciences will be receiving direct access to the important US Market through the Viaflo sales network. Integra Biosciences also receives access to a complete line of new and innovative handheld pipetting systems and associated plastic disposables. Viaflo will receive strong representation and access to European and global markets through Integra Biosciences and their large network of specialist distributors. In the USA - Viaflo will also benefit from selling the complimentary, well recognised, and established Integra Biosciences product portfolio. The Integra Biosciences and Viaflo products complement each other perfectly.
The new group, in the last 2 years has translated customer needs into the introduction of many new innovative and reliable products. With specialists in sales, marketing, research, development and manufacturing it maintains close relations and collaborations with customers worldwide for the purpose of providing cutting edge technologies to the health care industry. As a result of constant growth achieved over recent years, Integra Biosciences has announced that it will also move from its current location into a larger new modern industrial building in Zizers, Switzerland.
Circle no. 393
LABORATORY PRODUCTS
New-Shape UVette
The first fully UV-transparent disposable cuvette has a new improved shape. With a larger optical window, open side walls and easy-to- read path length indication, the patented Eppendorf UVette®
is even more user-friendly
and still delivers the same excellent results. As a perfect example of Eppendorf’s expertise in the production of high quality consumables, the UVette offers superb purity, convenience and precision for spectrophotometric analysis in the UV and VIS range.
The new-shape Eppendorf UVette is particularly suited to measurements of precious samples, quantification of low concentrations and recovery of samples for downstream applications.
The larger optical window reduces stray light effects and enhances the new UVette’s compatibility with instruments from other suppliers. The open side wall design gives greater sample visibility. A single 90º rotation provides two optical path lengths. The easy-to- read path length indication enables users to identify quickly the correct orientation (2mm and 10mm) for their application.
UVettes are manufactured from crystal clear plastic which is UV and VIS-transparent between 220 nm and 1,600 nm. Pipetting can be monitored clearly, volume markings show 500 µl and 1,000 µl, while the UVette’s design prevents the capillary effect, so that liquids remain in the centre of the measuring area even low volumes of > 50µl. The frosted grip is convenient for labelling and the inward facing optical windows provide superior protection against scratches.
Individually packaged, UVettes are PCR clean and protein-free to recover samples without the risk of degradation or contamination.
If this purity is not necessary, the economical UVette routine pack is also available. As well as being the ideal partner for the Eppendorf BioPhotometer plus, the UVette can be used in other photometers or spectrometers in conjunction with an adapter.
Circle no. 392
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