Alfred Wöhlk

Alfred Wöhlk (also: Woehlk, Wøhlk; born July 25, 1868 in Frederikshavn , Denmark ; † March 2, 1949 in Copenhagen ) was a Danish chemist and pharmacist .

Live and act

Alfred Wöhlk was the eighth of eleven children of his parents Carl Andreas Nicolai Wöhlk and Clara Wilhelmine Wöhlk, nee Nod. He studied at the Pharmaceutical College in Copenhagen , where he then worked and published in German. In 1910 he became the owner of Trianglen pharmacy in Copenhagen, which he ran until his death in 1949; at the same time he published for Danmarks Farmaceutiske Selskab (Denmark's Pharmaceutical Society) and invented the drug Magnyl , a Danish variant of ASA with magnesium oxide .

Wöhlk rehearsal

In 1904 Alfred Wöhlk worked with various sugars and tried to find a detection reaction with various alkaline substances . He almost wanted to discard an experiment with ammonia water after half an hour, when he discovered a reddish color, which was only found with lactose and maltose among the sugars used. This was an important discovery, because a detection reaction that could distinguish reducing monosaccharides (e.g. glucose) from reducing disaccharides (e.g. lactose, maltose) did not exist at that time. The Wöhlk sample was improved a year later by the Innsbruck urology professor Hans Malfatti , who used it in the clinical laboratory, by adding three drops of potassium hydroxide solution , since strictly alkaline conditions (pH 12-13) exist for the Wöhlk sample to be successful have to. The Wöhlk sample was used until the 1960s in the urology laboratory to differentiate dangerous gestational diabetes from harmless congestion (lactosuria), but also in academic teaching, especially in pharmacy studies and in food chemistry internships. The Wöhlk test for the detection of lactose and maltose has experienced a renewed upswing since 2016 because it can be used in chemistry classes as semi-quantitative proof of the very different lactose content of dairy products, which is relevant for people with lactose intolerance . Even at the end of a standard school experiment, the breakdown of starch by salivary amylase , it is used to detect the disaccharide maltose, which is the main product, alongside glucose , isomaltose and other incidental residues of endohydrolytic breakdown. The Wöhlk sample can be replaced by Fearon's test since 1942 and by a very low concentrated, alkaline solution of hexamethylenediamine since 2019 . This avoids the use and exposure of ammonia .

Individual evidence

↑ Alfred Wøhlk 1868-1949 In: slaegtprojekt.dk , accessed on February 16 2018th
^ 150 Years Alfred Wöhlk: Education: ChemistryViews. In: chemistryviews.org. July 25, 2018, accessed April 29, 2018 .
↑ ^a ^b Klaus Ruppersberg, Julia Hain: The rediscovery of the Wöhlk sample. In: ChiuZ . No. 51, 2017, pp. 106–111, doi: 10.1002 / ciuz.201600744 .
^ ^A ^b Alfred Wöhlk: About a new reaction to milk sugar and maltose . In: Journal for analytical chemistry . tape 43 . JF Bergmann, 1904, p. 670 ( limited preview in Google Book search).
^ Alfred Wöhlk: For the investigation of the urotropin . In: Journal for analytical chemistry . tape 44 . JF Bergmann, 1905, p. 765 ( limited preview in Google Book search).
↑ Klaus Ruppersberg, Julia Hain: The experiment. In: Chemkon . Vol. 23 (2016), H. 2, pp. 90-92, doi: 10.1002 / ckon.201610272 .
↑ Klaus Ruppersberg, Julia Hain, Petra Mischnik: On the trail of the red color: A historical proof of lactose rediscovered. In: Chemkon . Vol. 24 (2017), H. 4, pp. 302–503, doi: 10.1002 / ckon.201790012 .
↑ Ruppersberg, Klaus: Starch digestion by saliva - what does it actually come out of? A simple maltose detection at the end of the enzymatic hydrolysis of amylose and the surprising presence of glucose in a ratio of 1:15. In: MNU Journal. Vol. 69 (2016), H. 5, pp. 325–328, urn : nbn: de: 0111-pedocs-150973 .
↑ Klaus Ruppersberg, Horst Klemeyer: Lactose rapid test: How can you detect milk sugar in 60 seconds? In: CHEMKON . Wiley-Verlag, January 23, 2020, ISSN 0944-5846 , doi : 10.1002 / ckon.201900064 .

personal data
SURNAME	Wöhlk, Alfred
ALTERNATIVE NAMES	Woehlk, Alfred; Wøhlk, Alfred
BRIEF DESCRIPTION	Danish chemist and pharmacist
DATE OF BIRTH	July 25, 1868
PLACE OF BIRTH	Frederikshavn , Denmark
DATE OF DEATH	March 2, 1949
Place of death	Copenhagen

[1] Alfred Wøhlk 1868-1949 In: slaegtprojekt.dk , accessed on February 16 2018th

[chemistr-368150-2] 150 Years Alfred Wöhlk: Education: ChemistryViews. In: chemistryviews.org. July 25, 2018, accessed April 29, 2018 .

[:0-3] Klaus Ruppersberg, Julia Hain: The rediscovery of the Wöhlk sample. In: ChiuZ . No. 51, 2017, pp. 106–111, doi: 10.1002 / ciuz.201600744 .

[:1-4] A ^b Alfred Wöhlk: About a new reaction to milk sugar and maltose . In: Journal for analytical chemistry . tape 43 . JF Bergmann, 1904, p. 670 ( limited preview in Google Book search).

[5] Alfred Wöhlk: For the investigation of the urotropin . In: Journal for analytical chemistry . tape 44 . JF Bergmann, 1905, p. 765 ( limited preview in Google Book search).

[6] Klaus Ruppersberg, Julia Hain: The experiment. In: Chemkon . Vol. 23 (2016), H. 2, pp. 90-92, doi: 10.1002 / ckon.201610272 .

[rhm-7] Klaus Ruppersberg, Julia Hain, Petra Mischnik: On the trail of the red color: A historical proof of lactose rediscovered. In: Chemkon . Vol. 24 (2017), H. 4, pp. 302–503, doi: 10.1002 / ckon.201790012 .

[8] Ruppersberg, Klaus: Starch digestion by saliva - what does it actually come out of? A simple maltose detection at the end of the enzymatic hydrolysis of amylose and the surprising presence of glucose in a ratio of 1:15. In: MNU Journal. Vol. 69 (2016), H. 5, pp. 325–328, urn : nbn: de: 0111-pedocs-150973 .

[9] Klaus Ruppersberg, Horst Klemeyer: Lactose rapid test: How can you detect milk sugar in 60 seconds? In: CHEMKON . Wiley-Verlag, January 23, 2020, ISSN 0944-5846 , doi : 10.1002 / ckon.201900064 .