Salkowski reagent

Auterhoff described a reagent made up of 4-(dimethylamino)-benzaldehyde, sulfuric acid with additional iron(lll) ions as Van Urk s reagent solution . A more correct name would have been Van Urk-Salkowski reagent, since the Salkowski reagent (iron(lll) chloride/sulfuric acid) has been used alongside the Van Urk s reagent [8]. 

Van Urk-Salkowski Reagent Wurster s Blue Reagent Wurster s Red Reagent... 

Salicylsalicin la 195,196 Salinomycin lb 446 Salithione la 151 Salkowski reagent lb 237 Salonitenolide lb 290 Salsonilol lb 312... 

Iodides Cinnamaldehyde/hydrochloric acid 4-N,N- dimethylaminocinnamaldehyde Ehrlich reagent Ferric chloride (0.001 M) in 5% perchloric acid Naphthoquinone/perchloric acid Perchloric acid (5%)/ferric chloride (0.001 M) Prochazka reagent Salkowski reagent van Urk (or Stahl) reagent Xyanthydrol (0.1% in acidified ethanol) Sonnenschein test... 

Both the Salkowski reagents (Nos. 104 and 108) yield reaction products with differentiating colours many of the products fluoresce... 

Inhibition of tomato and barley plants growing in soils infested with Centaurea repens (knapweed) was reported by Fletcher and Renney (38). A toxic component was isolated in highest concentration from the foliage of knapweed. The inhibitor was considered to be an indole alkaloid or auxin precursor because of its ultraviolet absorption spectrum and the positive reactions obtained with Salkowski and Ehrlich reagents. The presence of the inhibitor was considered to explain partially the rapid establishment of Centaura spp. in almost pure stands. 

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