Kemesta

 

This document describes a method for the determination of inorganic arsenic in algae by anion-exchange HPLC-ICP-MS following water bath extraction. Inorganic arsenic consists of arsenite, As(III) and arsenate, As(V). A representative test portion of the sample is treated with a diluted nitric acid and hydrogen peroxide solution in a heated water bath. Hereby the arsenic species are extracted into solution and As(III) is oxidised to As(V). The inorganic arsenic is selectively separated from other arsenic compounds using anion exchange HPLC (High Performance Liquid Chromatography) coupled on-line to the element-specific detector ICP-MS (Inductively Coupled Plasma Mass Spectrometry) for the determination of the mass fraction of inorganic arsenic. External calibration with solvent matrix-matched standards is used for quantification of the amount of inorganic arsenic. The method is based on method EN16802: Inorganic arsenic in food of plant and marine origin by HPLC-ICPMS, but covers more algae species. The present AsSugar species in certain algae can cause As peaks which might overlap with the As peaks related to the inorganic As. The current method includes a gradient elution method with quality criteria to ensure a correct identification of the inorganic arsenic.

 

This document describes a method for determining the total protein content of algal biomass. Therefore, an existing method for measurement and calculation will be adapted. The method consists of the measurement of the nitrogen content by a practical test method and the calculation of the protein content by a coefficient. The document will describe the test method for nitrogen measurement. As the coefficient usually used for protein determination (6.25) is too high for algae, the document will give a recommendation for a coefficient which is more specific to algae and thereby more accurate.

 

This document specifies the dimensions, the method of sampling and the preparation of the test specimens, also the conditions for performing the low temperature tensile test perpendicular to the weld in order to determine the low temperature tensile welding factor. A low temperature tensile test can be used in conjunction with other tests (e.g. bend, tensile creep, macro) to assess the performance of welded assemblies, made from thermoplastics materials. The low temperature tensile welding factor and the appearance of the fracture surface provide a guide regarding the ductility of the joint and the quality of the work. The test is applicable to co-axial or co-planar welded assemblies made from thermoplastics materials filled or unfilled, but not reinforced, irrespective of the welding process used. The test is not applicable for co-axial welded assemblies of an external diameter less than 20 mm.

 

This document specifies methods for the manual ultrasonic examination of heated tool, electrofusion, extrusion and hot gas joints in plastics materials. It applies to joints in single wall pipes and plates. The range of thicknesses covered is from 10 mm to 100 mm. This document does not specify acceptance levels of the indications.

 

This document specifies a method for the determination of di-tert-butyl peroxide (DTBP) and 2, 5-Dimethyl-2, 5-di (tert-butylperoxy) hexane (DBPH) in plastics by using gas chromatography. This document is applicable to the determination of the content of residual peroxides in plastics and their products, which use peroxides as a degradation agent or crosslinking agent during plastics processing, or as an additive during polymerization, thereby remaining in degraded polypropylene, crosslinked polyethylene, polystyrene and other plastics.

 

This document specifies a method for the quantitative determination of total uronic acids by High-Performance Anion Exchange Chromatography coupled with Pulsed Amperometric Detection (HPAEC-PAD) after acid hydrolysis of the samples. It provides a single analysis method for determining mannuronic, glucuronic, and guluronic acids in brown seaweed and alginate products.

 

This document specifies a laboratory method for the quantification of phycocyanin content in the genus Arthrospira (Spirulina) by a spectrophotometric method.

 

This European standard specifies a laboratory method for the determination of the carotenoid content in microalgae. The method is based on the development of the chlorophyll a standard, which resulted in prEN 18034. This method has been validated for the microalgae species Nannochloropsis and Phaodactlylum. This standard is only validated for fucoxanthin, beta carotene and lutein content, but could be used for other carotenoids as well. Given small adaptations to be able to measure smaller concentrations, this method could also be used for macro algae. This standard is developed in CEN/TC 454/WG 6 Product test methods.