Extraction of the natural indigo carmine pigment from the Isatis plant, characterization and dyeing of wool

Abstract

Natural indigo is hardly used anymore, replaced by synthetic indigo. Considered to be more powerful and more intense. The aim of this study is to optimize the method of extracting indigo carmine from the Isatis plant located in the Timhdit region of Morocco, during the fermentation period of the extracted liquid (pH = 10) and by adding 10% sugar it was possible to increase the yield by 0.5% indigo carmine blue powder to 0.9%. The main effect of applying centrifugation at 7000 rpm instead of conventional filtration is the reduction of the time from 30 min to 5 min as well as the reduction of the loss of traces of indigo in the filter papers by easily recovering the blue powder in the form of sediment in the centrifuge tubes. The extracted pigment is characterized by the infrared which confirmed the structure of the indigo carmine obtained, by visible UV spectroscopy, the maximum absorption of which is approximately 598 nm. This blue pigment was applied to the wool fibres by optimizing the dyeing procedure (T = 50 ° C and pH=10) with a 1/100 bath ratio and a 35 min soaking time. Dyed wool sample has reached a rigid fixation confirmed by the test for fastness washing 105-C06 and to friction 105 -X12.

From Adsorbent to Photocatalyst: The Sensitization Effect of SnO2 Surface towards Dye Photodecomposition

“…In the range of 800–1400 cm −1 are present bands that can be attributed to N–O (880 cm −1 ), S–O (1044 cm −1 ), C–O (1084 cm −1 ), and OC–O=H vibrations (1161 and 1240 cm −1 (δ O–H + ν C–O )) [ 28 , 29 ]. These bands are characteristic of indigo carmine (IC).…”

“…These bands are characteristic of indigo carmine (IC). The vibration modes from 2800 to 3000 cm −1 can be assigned to the asymmetric (2851, 2871 cm −1 ) and symmetric (2920, 2955 cm −1 ) C–H stretching in CH 3 and CH 2 chains [ 28 , 30 ]. It is also worth noting that the 1st-IC sample shows some degree of fluorescence, which is characteristic of organic compounds (background elevation).…”

In situcopper nanoparticle immobilization on the indigo carmine-functionalized chitosan: a versatile biocatalyst towards CO2fixation and click reactions in water

“…Also, an absorption spectrum with a less intense peak around 1600 cm −1 and another more intense at 1410 cm −1 were observed and attributed to CO and CC stretching vibrations, respectively. 48 In the CS FT-IR spectrum, broad multiple peaks can be seen between 3200–3700 cm −1 related to the stretching of –OH and –NH 2 groups with intermolecular and intramolecular hydrogen bonds. The polysaccharide skeleton indicating –C–O– and –C–N– stretching frequencies appeared in the range of 1300–1450 cm −1 and 1000–1200 cm −1 , respectively.…”

Indigo Carmine in a Food Dye: Spectroscopic Characterization and Determining Its Micro-Concentration through the Clock Reaction

“…The chemical formula of indigo carmine [ 11 ] ((2E)-3-oxo-2-(3-oxo-5-sulfonato-1,3-dihydro-2H-indol-2-ylidène)-5-indolinesulfonate de disodium), possessing a molar mass of 466.36 g/mol, is presented in Figure 1 [ 12 ].…”

“…Due to the potential toxicity and harmful effects of indigo carmine on the ecosystem and biodiversity, its presence and concentration must be reliably determined. Different methods have been proposed to identify and quantify indigo carmine in wide-range samples, based mainly on UV/Vis spectrometry [ 14 , 15 , 16 , 17 , 18 ], electrochemical techniques [ 19 , 20 , 21 ], chromatography [ 22 , 23 , 24 ], FTIR spectroscopy [ 12 , 25 ], as well as advanced digital imaging techniques [ 26 , 27 ]. Understandably, all of these techniques have different sensitivity and accuracy of indigo carmine detection mainly depending on sample nature (to be more precise on its matrix).…”