On-line SPE–UHPLC method using fused core columns for extraction and separation of nine illegal dyes in chilli-containing spices

• Published in: Talanta (Oxford) Vol. 130; pp. 433 - 441
• Main Authors: Khalikova, Maria A., Šatínský, Dalibor, Šmidrkalová, Tereza, Solich, Petr
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2014
• Subjects: Azo Compounds - chemistry; Capsicum - chemistry; Chilli-containing samples; Chromatography, High Pressure Liquid - methods; Coloring Agents - chemistry; Coloring Agents - isolation & purification; Column switching; Food Analysis - methods; Food Coloring Agents - chemistry; Fused core column; Illegal red Sudan dyes; Indicators and Reagents - chemistry; Naphthols - chemistry; On-line solid phase extraction; Online Systems; Solid Phase Extraction - methods; Spices - analysis; UHPLC; Chilli-containing samples; Column switching; Illegal red Sudan dyes; UHPLC; Fused core column; On-line solid phase extraction
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2014.07.038

The presented work describes the development of a simple, fast and effective on-line SPE–UHPLC–UV/vis method using fused core particle columns for extraction, separation and quantitative analysis of the nine illegal dyes, most frequently found in chilli-containing spices. The red dyes Sudan I–IV, Sudan Red 7B, Sudan Red G, Sudan Orange G, Para Red, and Methyl Red were separated and analyzed in less than 9min without labor-consuming pretreatment procedure. The chromatographic separation was performed on Ascentis Express RP-Amide column with gradient elution using mixture of acetonitrile and water, as a mobile phase at a flow rate of 1.0mLmin−1 and 55°C of temperature. As SPE sorbent for cleanup and pre-concentration of illegal dyes short guard fused core column Ascentis Express F5 was used. The applicability of proposed method was proven for three different chilli-containing commercial samples. Recoveries for all compounds were between 90% and 108% and relative standard deviation ranged from 1% to 4% for within- and from 2% to 6% for between-day. Limits of detection showed lower values than required by European Union regulations and were in the range of 3.3–10.3µgL−1 for standard solutions, 5.6–235.6µgkg−1 for chilli-containing spices. [Display omitted] •Method for determination of illegal Sudan dyes in chilli containing spices was developed.•Method shows on-line SPE–UHPLC separation system with rapid sample pretreatment.•On-line dyes extraction was developed using fused core precolumns.•Method shows innovative approach in fused core columns using both dimensions.