• Home
  • Search Results
  • Optimization of magnetic stirring assisted dispersive liquid-liquid microextraction of rhodamine B and rhodamine 6G by response surface methodology: Application in water samples, soft drink, and cosmetic products.

Optimization of magnetic stirring assisted dispersive liquid-liquid microextraction of rhodamine B and rhodamine 6G by response surface methodology: Application in water samples, soft drink, and cosmetic products.

Talanta (2015-04-18)
Elias Ranjbari, Mohammad Reza Hadjmohammadi
ABSTRACT

An exact, rapid and efficient method for the extraction of rhodamine B (RB) and rhodamine 6G (RG) as well as their determination in three different matrices was developed using magnetic stirring assisted dispersive liquid-liquid microextraction (MSA-DLLME) and HPLC-Vis. 1-Octanol and acetone were selected as the extraction and dispersing solvents, respectively. The potentially variables were the volume of extraction and disperser solvents, pH of sample solution, salt effect, temperature, stirring rate and vortex time in the optimization process. A methodology based on fractional factorial design (2(7)(-2)) was carried out to choose the significant variables for the optimization. Then, the significant factors (extraction solvent volume, pH of sample solution, temperature, stirring rate) were optimized using a central composite design (CCD). A quadratic model between dependent and independent variables was built. Under the optimum conditions (extraction solvent volume=1050µL, pH=2, temperature=35°C and stirring rate=1500rpm), the calibration curves showed high levels of linearity (R(2)=0.9999) for RB and RG in the ranges of 5-1000ngmL(-1) and 7.5-1000ngmL(-1), respectively. The obtained extraction recoveries for 100ngmL(-1) of RB and RG standard solutions were 100% and 97%, and preconcentration factors were 48 and 46, respectively. While the limit of detection was 1.15ngmL(-1) for RB, it was 1.23ngmL(-1) for RG. Finally, the MSA-DLLME method was successfully applied for preconcentration and trace determination of RB and RG in different matrices of environmental waters, soft drink and cosmetic products.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Methanol, anhydrous, 99.8%
Sigma-Aldrich
Methanol, HPLC Plus, ≥99.9%, poly-coated bottles
Sigma-Aldrich
Acetonitrile, anhydrous, 99.8%
Sigma-Aldrich
Dodecane, anhydrous, ≥99%
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Sigma-Aldrich
1-Octanol, anhydrous, ≥99%
Sigma-Aldrich
2-Ethyl-1-hexanol, ≥99.6%
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
Acetone, suitable for HPLC, ≥99.9%
Sigma-Aldrich
2-Ethyl-1-hexanol, ≥99%, FG
Sigma-Aldrich
1-Octanol, ≥98%, FCC, FG
Millipore
Acetonitrile solution, suitable for HPLC, acetonitrile:water 5:95% (v/v), 10 mM Ammoniumbicarbonate, pH 10,0
Supelco
Methanol solution, contains 0.10 % (v/v) formic acid, UHPLC, suitable for mass spectrometry (MS), ≥99.5%
Sigma-Aldrich
Acetonitrile, electronic grade, 99.999% trace metals basis
Supelco
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 5 mm × 8 in.
Sigma-Aldrich
1-Octanol, natural, ≥98%, FCC
Sigma-Aldrich
Methanol, NMR reference standard
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid
Sigma-Aldrich
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 3 mm × 8 in.
Sigma-Aldrich
Methanol-12C, 99.95 atom % 12C