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This article describes a simple and sensitive method for chromium(VI) determination in children's toys. The solution to be analyzed is prepared in accordance with DIN EN 71. Not only VIS detection but also post-column derivatization using diphenylcarbizide are parts of this method. The procedure described here is suitable for the precise determination of hexavalent chromium in the single-digit ppt range and, in addition, fulfils without difficulty the limit value of 10 ppt prescribed by the EU directive 2009/48/EC.

Underestimation of quality control (QC) processes is one of the major factors leading to internal and external product failure, which have been reported to cause a loss of turnover between 10–30%. As a result, many different norms are put in place to support manufacturers with their QC process. However, time to result and the associated costs for chemicals can be quite excessive, leading many companies to implement near-infrared spectroscopy (NIRS) in their QC process. This paper illustrates the potential of NIRS and displays cost saving potentials up to 90%.

Hydroxyl is an important functional group and knowledge of its content is required in many intermediate and end-use products such as polyols, resins, lacquer raw materials and fats (petroleum industry). The test method to be described determines primary and secondary hydroxyl groups. The hydroxyl number is defined as the mg of KOH equivalent to the hydroxyl content of 1 g of sample.The most frequently described method for determining the hydroxyl number is the conversion with acetic anhydride in pyridine with subsequent titration of the acetic acid released: H3C-CO-O-CO-CH3 + R-OH -> R-O-CO-CH3 + CH3COOH. However, this method suffers from the following drawbacks: - The sample must be boiled under reflux for 1 h (long reaction time and laborious, expensive sample handling) - The method cannot be automated - Small hydroxyl numbers cannot be determined exactly - Pyridine has to be used, which is both toxic and foul-smellingBoth standards, ASTM E1899-08 and DIN 53240-2, offer alternative methods that do not require manual sample preparation and therefore can be fully automated: The method suggested in ASTM E1899-08 is based on the reaction of the hydroxyl groups attached to primary and secondary carbon atoms with excess toluene-4-sulfonyl-isocyanate (TSI) to form an acidic carbamate. The latter can then be titrated in a non-aqueous medium with the strong base tetrabutyl- ammonium hydroxide (TBAOH). The method suggested in DIN 53240-2 is based on the catalyzed acetylation of the hydroxyl group. After hydrolysis of the intermediate, the remaining acetic acid is titrated in a non-aqueous medium with alcoholic KOH solution. The present work demonstrates and discusses an easy way to determine the hydroxyl number according to ASTM E1899-08 or DIN 53240-2 with a fully automated titrimetric system for a great variety of industrial oil samples.

This article demonstrates the utility of portable Raman spectroscopy as a versatile tool for process analytical technology (PAT) for raw material identification, in-situ monitoring of reactions in developing active pharmaceutical ingredients (APIs), and for real-time process monitoring. Raw material identification is done for verification of starting materials as required by PIC/S and cGMP, and can be readily done with handheld Raman. Portable Raman systems allow users to make measurements to bring process understanding and also provide proof of concept for the Raman measurements to be implemented in pilot plants or large-scale production sites. For known reactions which are repetitively performed or for continuous online process monitoring of reactions, Raman provides a convenient solution for process understanding and the basis for process control.

Raman spectroscopy’s use for process analytics in the pharmaceutical and chemical industries continues to grow due to its nondestructive measurements, fast analysis times, and ability to do both qualitative and quantitative analysis. Spectral preprocessing algorithms are routinely applied to quantitative spectroscopic data in order to enhance spectral features while minimizing variability unrelated to the analyte in question. In this technical note we discuss the main preprocessing options pertinent to Raman spectroscopy with real applications examples, and to review the algorithms available in B&W Tek and Metrohm software so that the reader becomes comfortable applying them to build Raman quantitative models.

Carbonyl compounds (CC) occur in many products, such as bio-oils and fuels, cyclic and acyclic solvents, flavors and mineral oils. Carbonyl compounds can be responsible for the instability of these products during storage or processing. Especially pyrolysis bio-oils are known to cause issues during storage, handling and upgrading. This bulletin describes an aqueous and a non-aqueous analytical titration method for the determination of carbonyl compounds by potentiometric titration.

4-Carboxybenzaldehyde, in the following referred to as 4-CBA, can be reduced directly at the dropping mercury electrode (DME) in an ammoniacal solution. After a very simple sample preparation it is now possible to determine the concentration of 4-CBA in terephthalic acid quickly and precisely by polarography down to the lower ppm range.

This Application Bulletin describes the determination of the thermostability of PVC in accordance with ISO 182 Part 3 using the dehydrochlorination method with the 895 Professional PVC Thermomat. The instrument permits fully automatic determination of the stability time. The test is suitable for monitoring the manufacture and processing of PVC products manufactured in the injection molding process, for their final clearance, characterization and for the comparison of PVC products and for testing the effectiveness of heat stabilizers.

Maleic and fumaric acid can be reduced electrochemically to succinic acid. In acidic solutions a differentiation of the two acids is not possible since both are reduced at the same potential. On the other hand, separation at pH 7.8...8.0 is easily possible since fumaric acid is now more difficult to reduce at the lower proton concentration (as a result of cis-trans isomerism) than maleic acid.

Polyisobutene (PIB) is an important raw material for a large range of products. Quality control requires the determination of the fluorine content. This task is easily done by Metrohm Combustion IC applying flame sensor technology and Inline Matrix Elimination.Keyword: pyrohydrolysis