Maltose-Schnelltest mit der Mikrowelle

Maltose quick test in a household microwave oven in 60 seconds

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Publication data


ByKlaus Ruppersberg
Original languageGerman
Published inNaturwissenschaften im Unterricht - Chemie, 31(179)
Pages49-50
Editor (Publisher)Friedrich Verlag
ISSN0946-2139, 0340-5479
Publication statusPublished – 09.2020

Usually, a Woehlk test for maltose detection after degradation of starch by salivary amylase lasts up to 30 minutes. In this case, a 10% ammonia solution is used, which gives off quickly and abundantly ammonia to the ambient air when heated. Ammonia is a highly flammable gas (H221) that is toxic by inhalation (H331, corrosive (EUH071) and may also cause damage to the skin and eyes (H314).) Since 1942, Fearon's Test has been used as a substitute. An aqueous solution of methylamine hydrochloride has to be alkalized with sodium hydroxide and must reach a pH of about 12.7. Methylamine hydrochloride is admitted for secondary school students and is also available at relatively low prices in the trade, but is not usual in experimental school lessons Therefore, it is all the more gratifying that in January 2019 with 1,6-diaminohexane an alternative could be found that is already present in many places (nylon rope trick). A 0.025 molar diaminohexane solution, which with 0.1 molar sodium hydroxide solution is adjusted to pH 13, a lactose can be detected by using beakers in a household microwave within 60 seconds. The article explains how with 1.7 mL of liquified diaminohexane the semi-annual needs of a school can be prepared as a ready-for-use solution and what you have to consider to handle the experiment either in a water bath or in a microwave oven safe and meaningful.