Ultrasound-assisted hydrophobic deep eutectic solvent based solid-liquid microextraction of Sudan dyes in spice samples.

An environmentally friendly, simple method was carried out with the help of an ultrasonic assisted solid-liquid microextraction technique using a new deep eutectic solvent (DES) for the extraction and determination of Sudan dyes (I-IV) in spice samples. In this method, parameters affecting the optimization were researched and optimized such as DES composition, DES volume, ultrasonic time, temperature and, centrifuge time. The analytical performance of the developed method was quite satisfactory, the R2 values were higher than 0.9989, and the limits of quantification were <1.17 μg g-1. Two different concentrations (10-50 μg g-1) were spiked to Chili peppers, paprika, cumin and sumac spices for the applicability and accuracy of the developed microextraction method. Some of these spices were found to contain Sudan I and IV dyes. The recovery values for spiked samples were found to be between 85.55% and 99.29% and relative standard deviations were found to be <3.17% when using a 10 μg g-1 Sudan dyes concentration. The results showed that the developed method can be successfully applied for extraction and determination of Sudan dyes in spice samples.

Sivrikaya Ozak S ，Yılmaz Y 《-》

Preparation of new hydrophobic deep eutectic solvents and their application in dispersive liquid-liquid microextraction of Sudan dyes from food samples.

Ge D ，Shan Z ，Pang T ，Lu X ，Wang B ... -  《-》

Determination of some red dyes in food samples using a hydrophobic deep eutectic solvent-based vortex assisted dispersive liquid-liquid microextraction coupled with high performance liquid chromatography.

Faraji M 《-》

Liquid-liquid microextraction of synthetic pigments in beverages using a hydrophobic deep eutectic solvent.

A method was developed for the determination of eight synthetic pigments in beverage samples by liquid-liquid microextraction followed by high performance liquid chromatography. Using hydrophobic deep eutectic solvent (DES) as the microextraction solvent, several key parameters were optimized, including the type and volume of the hydrophobic DES, pH value, vortex time and salt content. Detection limits were in the range 0.016-1.12 ng/mL, recoveries were in the range 74.5-102.5% and relative standard deviations were <5.4%. The method is simple, green and practical, and could be applied to the extraction and determination of synthetic pigments in beverages.

Zhu S ，Zhou J ，Jia H ，Zhang H ... -  《-》

Nonionic surfactants based hydrophobic deep eutectic solvents for liquid-liquid microextraction of Sudan dyes in tomato chili sauces.

A new type of high-density hydrophobic deep eutectic solvents (DESs) were synthesized with nonionic surfactants as hydrogen bond acceptors and hexafluoroisopropanol (HFIP) as hydrogen bond donor. Brij-35 was selected as the optimal nonionic surfactant for the preparation of Brij-35-HFIP-DES (molar ratio 1:20). A vortex-assisted DES-based liquid-liquid microextraction method was proposed for determination of Sudan dyes in tomato chili sauces. The whole pretreatment process only needs 5 min and 1.1 mL of organic solvent. The method with HPLC-DAD shows high efficiency (enrichment factors 89-176 and extraction rates 61.0-74.6%) and good performance with linearity (R ≥ 0.9997) in 0.04-2 μg g-1 range, detection limits of 0.0045-0.0118 μg g-1, recoveries of 91.6-104.5% and intra-/inter-day precision below 8.0%. A "DES in water in DES" aggregate microstructure was observed in DES-rich phase. The proposed method is simple, quick, eco-friendly, and suits for the efficient extraction and accurate determination of Sudan dyes in tomato chili sauces.

Chen J ，Li X ，Huang A ，Deng W ，Xiao Y ... -  《-》