Chemie a potravinářství

Oblast zaměření: Lepidla
Komise : CEN/TC 193 (Adhesives)
Původce: CEN
K připomínkám do: 21.07.2018
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This International Standard specifies a dynamic impact wedge method for the determination of the cleavage resistance under impact loading of high-strength adhesive bonds between two adherends, when tested under specified conditions of preparation and testing. This test procedure does not provide design information.

The method allows a choice of sheet metal or fiber reinforced plastic substrates corresponding to those materials frequently used in industry, e.g. for automotive applications.

Oblast zaměření: Potravinářské produkty
Komise : CEN/TC 327 (Animal feeding stuffs: Methods of sampling and analysis)
Původce: CEN
K připomínkám do: 20.08.2018
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This document describes a method for the determination of individual ergot alkaloids and tropane alkaloids in unprocessed cereals and cereal-based compound feeds by high performance liquid chromatography with tandem mass spectrometry (LC-MS/MS).

This method has been successfully validated by collaborative trial in the following matrices: rye, barley, wheat, complete feed for bovine, porcine and poultry. Validation in buckwheat produced acceptable results, but the relative standard reproducibility was higher for most analytes in comparison with the other matrices. This may be related to the matrix. The validated range of the method is approximately 10 µg/kg to 250 µg/kg for individual alkaloids. Determination of concentrations above 250 µg/kg is possible by applying a higher spiking level and dilution of the sample extract, but this has not been validated in the collaborative trial.

The method is applicable for the determination, by means of one-point standard addition to the sample, of ergocornine in the tested range of 12 µg/kg to 221 µg/kg, ergocorninine in the tested range of 9 µg/kg to 196 µg/kg, ergocristine in the tested range of 14 µg/kg to 312 µg/kg, ergocristinine in the tested range of 12 µg/kg to 258 µg/kg, α-ergocryptine in the tested range of 10 µg/kg to 184 µg/kg, α-ergocryptinine in the tested range of 8 µg/kg to 171 µg/kg, ergometrine in the tested range of 12 µg/kg to 174 µg/kg, ergometrinine in the tested range of 3 µg/kg to 172 µg/kg, ergosine in the tested range of 12 µg/kg to 226 µg/kg, ergosinine in the tested range of 9 µg/kg to 273 µg/kg, ergotamine in the tested range of 11 µg/kg to 443 µg/kg, ergotaminine in the tested range of 10 µg/kg to 273 µg/kg, atropine in the tested range of 16 µg/kg to 252 µg/kg and scopolamine in the tested range of 15 µg/kg to 246 µg/kg.

Komise : CEN/TC 139 (Paints and varnishes)
Původce: CEN
K připomínkám do: 1.09.2018
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This part of ISO 3233 specifies a method for determining the non-volatile matter by volume (NVv) of coating materials by determining the practical dry-film density. This method determines the volume percentage of non-volatile matter in paints, varnishes and related products by measuring the density of a dry coating for any specified temperature range and period of drying or curing.

Using the non-volatile matter by volume results obtained in accordance with this part of ISO 3233, it is possible to calculate the practical spreading rate of coating materials.

This method specifies an additional shape of plate to those described in ISO 3233‑1 and is suitable for all products which can be applied by dipping.

This part of ISO 3233 is not applicable to coating materials which exceed the critical pigment volume concentration (CPVC).

Komise : CEN/TC 139 (Paints and varnishes)
Původce: CEN
K připomínkám do: 1.09.2018
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This document specifies a method for determining the non-volatile-matter content by mass of paints, varnishes, binders for paints and varnishes, polymer dispersions and condensation resins such as phenolic resins (resols, novolak solutions etc.).

The method is also applicable to formulated dispersions containing fillers, pigments and other auxiliaries (e.g. thickeners, film-forming agents). For the method to be usable for unplasticized polymer dispersions and rubber lattices, the non-volatile residue (which consists essentially of the polymeric material and of small quantities of auxiliaries such as emulsifiers, protective colloids, stabilizers, solvents added as film-forming agents and – especially for rubber latex concentrate – preserving agents) has to be chemically stable under the test conditions. For plasticized samples, the residue, by definition, normally includes the plasticizer.

NOTE 1       The non-volatile-matter content of a product is not an absolute quantity but depends upon the temperature and period of heating used for the determination. Consequently, when using this method, only relative and not true values for non-volatile-matter content are obtained owing to solvent retention, thermal decomposition and evaporation of low molecular mass constituents. The method is therefore primarily intended for testing different batches of the same type of product.

NOTE 2       This method is suitable for synthetic rubber latices provided heating for a specific period of time is considered appropriate (ISO 124 specifies heating until the loss in mass of a 2 g test portion following successive periods of heating is less than 0,5 mg).

NOTE 3       In-house methods for determining non-volatile matter often include drying with infrared or microwave radiation. Standardization of such methods is not possible, since they are not generally applicable. Several polymer compositions tend to decompose during such treatment and therefore give incorrect results.

ISO 3233 (all parts) specifies test methods for determining the volume of non-volatile matter in paints, varnishes and related products.

Komise : CEN/TC 139 (Paints and varnishes)
Původce: CEN
K připomínkám do: 2.09.2018
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This document describes a number of methods that are applicable to the measurement of the thickness of coatings applied to a substrate. Methods for determining wet-film thickness, dry-film thickness and the film thickness of uncured powder layers are described. Reference is made to individual standards where these exist. Otherwise the method is described in detail.

An overview on the methods is given in Annex A, in which the field of application, existing standards and the precision are specified for the individual methods.

This document also defines terms concerning the determination of film thickness.

NOTE          This standard consistently enumerateds the individual coatings applied in a multi-layer system by referring to the first coating applied on the substrate as coating 1. Some other standards referring to individual test methods enumerate in reverse order