Blue Wool Reference

Fastness to Light. The ISO test for colorfastness to light is DajlightlSO 105-B01. The textile specimen is exposed to daylight under prescribed conditions, including protection from rain, along with a series of blue wool reference samples that fade at defined, prescribed, different rates. 

As an example, five different synthetic colorants (Tartrazine, Sunset Yellow, Ponceau 4R, Amaranth, and Brilliant Blue FCF) from drinks and candies were separated on a polyamide adsorbent at pH 4, eluted with an alkaline-ammonia solution. By another method, 13 synthetic food colorants were isolated from various foods using specific adsorption on wool. After elution with 10% ammonia solution and gentle warming, an absorption spectrum of the resulting colorant solution was recorded, compared to the reference spectra of pure colorants, and identified by linear regression analysis. ... 

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