Flow injection methods for the determination of retinol and α‐tocopherol using lucigenin‐enhanced chemiluminescence

Abstract

Flow injection (FI) methods are reported to determine retinol and α-tocopherol based on its enhancement affect of lucigenin chemiluminescence (CL) in alkaline medium. Surfactants including Brij-35, Triton X-100, cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate have been reported for the first time to enhance lucigenin CL intensity in the presence of retinol and α-tocopherol. With Brij-35, the CL intensity was enhanced by 67% for retinol and 58% for α-tocopherol. CTAB was found to enhance the CL intensity by 16% for retinol whereas for α-tocopherol, the CL intensity was quenched up to 95%. Retinol could be determined specifically in the presence of α-tocopherol using CTAB. The calibration graphs were found to be linear up to 1.43 mg/L (R(2) = 0.9985, n = 8) with a detection limit (3s) of 1.43 × 10(-3) mg/L for retinol and 2.15 mg/L (R(2) = 0.9989; n = 8) with a detection limit (3s) of 4.31 × 10(-4) mg/L for α-tocopherol. An injection throughput of 120/h, and relative standard deviations of 0.9-2.8% (n = 4) were achieved in the concentration range studied. The influence of common ions, excipients in pharmaceutical formulations and related organic compounds on the determination of retinol and α-tocopherol individually was studied. The proposed methods were applied to determine retinol and α-tocopherol in pharmaceutical formulations and human blood serum. The results did not differ significantly from the CL method and HPLC reference method at 95% confidence level.

Mechanism of alcohol‐enhanced lucigenin chemiluminescence in alkaline solution

“…Lucigenin ( N , N ′‐dimethyl‐9,9′‐biacridinium dinitrate, Luc 2+ ) is a classic organic chemiluminescence (CL) agent that has been used extensively in analytical science, such as in the determination of metal ions , chloride and phosphate ; in assays of biologically important reducing compounds , including vitamins , sugars and bilirubin ; as probes for superoxide anion (O 2 •− ) production in enzymatic and cellular systems ; in the quantification of superoxide dismutase (SOD) or for SOD mimic activities ; and in the detection of alkaline phosphatase (ALP) , and generally in enzyme immunoassays. The applications of these analytical methods with lucigenin are mainly based on the enhancement or inhibition of the CL emission.…”

“…Lucigenin (N,N′-dimethyl-9,9′-biacridinium dinitrate, Luc 2+ ) is a classic organic chemiluminescence (CL) agent that has been used extensively in analytical science, such as in the determination of metal ions (1)(2)(3)(4)(5), chloride (6) and phosphate (7); in assays of biologically important reducing compounds (8)(9)(10), including vitamins (11), sugars (12) and bilirubin (13); as probes for superoxide anion (O 2…”

“…UV/Vis absorption spectra of lucigenin in the absence (a) and presence of 1,3-propanediol (b), glycerol (c) or DHA (d) under alkaline conditions. (a) a-h: 0, 5, 10, 15, 20, 25, 30, 35 min; (b) a-t: 0, 1, 2,3,4,5,6,7,8,9,10,11,12,13,14,15,20,25,30,35 min; (c) a-u: 0, 1, 2, 3, 4, 5,6,7,8,9,10,11,12,13,14,15,20,25,30,35, 40 min; (d) a-p: 0, 1, 2,3,4,5,6,7,8,9,10,15,20,25,30,35 min. 1,3-Propanediol, 5 mol/L; glycerol, 2.5 mol/L; DHA, 2.5 × 10 À4 mol/L; lucigenin, 1.0 × 10 À5 mol/L; NaOH, 0.1 mol/L.…”

Enhanced chemiluminescence of cerium(IV)–Tween 85 system and the analytical application

“…During the last 40 years, chemiluminescence (CL) has attracted extensive interest and has been developed as an important and powerful tool in different fields (1)(2)(3)(4)(5). The most notable characteristics of CL methods are higher sensitivity, simple instrumentation, lack of background scattering light interference and greater dynamic concentration range (6)(7)(8)(9)(10)(11). In recent years, some compounds have been widely used as CL reagents in analytical chemistry due to their highly CL intensity (12)(13)(14)(15)(16).…”

Vitamin A Determination in Milk Samples Based on the Luminol-Periodate Chemiluminescence System

“…A brief discussion on the possible CL reaction mechanism is also presented. Key Words flow injection analysis, chemiluminescence, vitamin A, human milk, nutritional assessment ceuticals and blood serum utilizing the potentials of FI based on Ru(bipyl)3 21 -Ce(IV) (25), acidified KMnO4-HCHO (26), lucigenin-NaOH-Brij-35 (27) and luminol-V(IV) (28) CL systems. In this manuscript, an FI method for the assay of retinyl acetate has been described based on its enhancing effect on the luminol-periodate CL reaction in an alkaline medium, which offered a simple apparatus and rapid means of detection.…”