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Design of a flow-through voltammetric sensor based on an antimony-modified silver electrode for determining lithol rubine B in cosmetics.

Lai-Hao W, Shu-Juan H - J Autom Methods Manag Chem (2011)

Bottom Line: For direct current (DC) mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.125 to 1.80 μg/mL was found.The detection limit of our method was approximately 2.0 ng/mL.Findings using HPLC-ECD and HPLC with an ultraviolet detector were comparable.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Chemistry, Chia Nan University of Pharmacy and Science, 60 Erh-Jen Road, Section 1, Jen Te, Tainan 71743, Taiwan.

ABSTRACT
Lithol Rubine B (LRB; the disodium salt of 3-hydroxy-4-[(4-methyl-2-sulfophenyl) azo]-2-naphthalenecarboxylic acid) was detected using high-performance liquid chromatography with an electrochemical (antimony film on silver) detector (HPLC-ECD). For direct current (DC) mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.125 to 1.80 μg/mL was found. The detection limit of our method was approximately 2.0 ng/mL. An antimony-modified silver detector was used to demonstrate that LRB is electrochemically reduced in acidic media and to analyze commercial cosmetics to determine their LRB content. Findings using HPLC-ECD and HPLC with an ultraviolet detector were comparable.

No MeSH data available.


Related in: MedlinePlus

Chromatograms obtained by LC-UV (a) and LC-ECD (b) from commercial cosmetics. Analysis conditions are identical to those listed in Figure 5.
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fig7: Chromatograms obtained by LC-UV (a) and LC-ECD (b) from commercial cosmetics. Analysis conditions are identical to those listed in Figure 5.

Mentions: Our proposed LC-EC method was used to determine Lithol Rubine B in cosmetic products. Chromatograms of a comparison of LC-UV (Figure 7(a)) and LC-EC (Figure 7(b)) for Lithol Rubine B in cosmetics show that the sensitivity for the Lithol Rubine B investigated was about two orders of a magnitude higher with LC-EC than with LC-UV detection; however, there were no significant differences in the values obtained using both types of analysis (Table 1).


Design of a flow-through voltammetric sensor based on an antimony-modified silver electrode for determining lithol rubine B in cosmetics.

Lai-Hao W, Shu-Juan H - J Autom Methods Manag Chem (2011)

Chromatograms obtained by LC-UV (a) and LC-ECD (b) from commercial cosmetics. Analysis conditions are identical to those listed in Figure 5.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3094699&req=5

fig7: Chromatograms obtained by LC-UV (a) and LC-ECD (b) from commercial cosmetics. Analysis conditions are identical to those listed in Figure 5.
Mentions: Our proposed LC-EC method was used to determine Lithol Rubine B in cosmetic products. Chromatograms of a comparison of LC-UV (Figure 7(a)) and LC-EC (Figure 7(b)) for Lithol Rubine B in cosmetics show that the sensitivity for the Lithol Rubine B investigated was about two orders of a magnitude higher with LC-EC than with LC-UV detection; however, there were no significant differences in the values obtained using both types of analysis (Table 1).

Bottom Line: For direct current (DC) mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.125 to 1.80 μg/mL was found.The detection limit of our method was approximately 2.0 ng/mL.Findings using HPLC-ECD and HPLC with an ultraviolet detector were comparable.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Chemistry, Chia Nan University of Pharmacy and Science, 60 Erh-Jen Road, Section 1, Jen Te, Tainan 71743, Taiwan.

ABSTRACT
Lithol Rubine B (LRB; the disodium salt of 3-hydroxy-4-[(4-methyl-2-sulfophenyl) azo]-2-naphthalenecarboxylic acid) was detected using high-performance liquid chromatography with an electrochemical (antimony film on silver) detector (HPLC-ECD). For direct current (DC) mode, with the current at a constant potential, and measurements with suitable experimental parameters, a linear concentration from 0.125 to 1.80 μg/mL was found. The detection limit of our method was approximately 2.0 ng/mL. An antimony-modified silver detector was used to demonstrate that LRB is electrochemically reduced in acidic media and to analyze commercial cosmetics to determine their LRB content. Findings using HPLC-ECD and HPLC with an ultraviolet detector were comparable.

No MeSH data available.


Related in: MedlinePlus