On-line phase-transfer catalysed dansylation of phenolic compounds followed by normal-phase liquid chromatography with fluorescence detection

Halvax, J.J.; Wiese, G.; Bennekom, W.P. van; Bult, A.

doi:10.1016/0731-7085(92)80049-s

Cited by 7 publications

(3 citation statements)

References 4 publications

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“…A number of other classical assays based on the fluorometric or chemiluminescence detection of dansyl derivatized estrogens have been reported. − The fluorescence is not related to EE per se, but rather originates from the dansyl moiety. Therefore, other endogenous estrogens and their metabolites that are coderivatized, are detected simultaneously .…”

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confidence: 99%

Derivatization of Ethinylestradiol with Dansyl Chloride To Enhance Electrospray Ionization: Application in Trace Analysis of Ethinylestradiol in Rhesus Monkey Plasma

et al. 2002

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The extensive metabolism and administration of low doses of ethinylestradiol (EE) in preclinical animal species necessitates a sensitive analytical method to quantify the drug at low picogram-per-milliliter concentrations in biological matrixes. A highly sensitive and accurate method based on the derivatization of EE with dansyl chloride coupled with liquid chromatography/tandem mass spectrometry is described. The dansyl derivatization of EE introduced a basic secondary nitrogen into the molecule that was readily ionized in commonly used acidic HPLC mobile phases. The derivative showed an intense protonated molecular ion at m/z 530 under positive turbo ion spray ionization. The collision-induced dissociation of this ion formed a distinctive product at m/z 171, corresponding to the protonated 5-(dimethylamino)naphthalene moiety. The selected reaction monitoring, based on the m/z 530 --> 171 transition, was highly specific for EE, since no background signal was observed from blank plasma obtained from rhesus monkeys. The limit of detection, at a signal-to-noise ratio of 5, was 0.2 fg/mL EE spiked into blank plasma. This allowed for a lower limit of quantitation of 5 pg/mL using a 50-microL plasma sample and 10-microL injection of dansylated derivative into the CTC-PAL Leap autosampler coupled to a Sciex API 4000 mass spectrometer. Using fast-gradient liquid chromatography, the analyte peak eluted at 1.6 min. The validation results showed high accuracy (% bias < 4) and precision (% CV < 7.5) at broad linear dynamic ranges (0.005-20 ng/mL), using deuterated EE as internal standard. Therefore, the facile dansyl derivatization coupled with tandem mass spectral analysis allowed the development of a highly sensitive and specific method for quantitation of trace levels of EE in the plasma of rhesus monkeys dosed orally and intravenously with EE.

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mentioning

confidence: 99%

Derivatization of Ethinylestradiol with Dansyl Chloride To Enhance Electrospray Ionization: Application in Trace Analysis of Ethinylestradiol in Rhesus Monkey Plasma

et al. 2002

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“…By pre-column derivatization with this fluorescent tag, serum estradiol 42 and various phenols 34,43 have been determined by LC with POCL detection. In order to accelerate the dansylation of phenolic compounds at room temperature, a two-phase transfer catalytic procedure was used, 34,43,44 after which excess label was removed by allowing the organic phase to pass through an amino-bonded SPE column. Furthermore, the sensitivity can be significantly improved for phenols carrying electronegative substituents by application of a post-column photochemical reaction.…”

Section: Optimization Of the Derivatization Conditionsmentioning

confidence: 99%

“…4-Chlorophenol, 3,4-dimethylphenol and 2,5-dimethylphenol were also included in this study to evaluate the presence of some substituents on the labelling reaction and CL detection of dansylated phenols. To overcome the problems associated with the use of the reported two-phase transfer catalytic procedure, 34,43,44 dansylation of phenols was carried out in a micellar medium, considering that the micelles could be a useful and clean alternative to the use of organic solvents and that they could increase the rate of the labelling reaction on the basis of a micellar catalytic effect. 48 CTAB and SDS at concentrations above their respective critical micellar concentration (CMC) were initially added to the derivatization solution (2.6 3 10 23 M Dns-Cl and 6.6 3 10 22 M sodium carbonate adjusted to pH 10.8) and the mixture underwent reaction for 15 min at 65 °C.…”

Section: Optimization Of the Derivatization Conditionsmentioning

confidence: 99%

Sensitive determination of low molecular mass phenols by liquid chromatography with chemiluminescence detection for the determination of phenol and 4-methylphenol in urine

Orejuela

Silva

2002

Analyst

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A rapid, reliable method for the routine determination of phenol and 4-methylphenol in urine samples by liquid chromatography with peroxyoxalate chemiluminescence detection was developed. Phenols were first cleaned up by passing the sample through a LiChrolut EN sorbent column and then derivatized straightforwardly with dansyl chloride (15 min at room temperature) thanks to the micellar catalytic effect provided by Triton X-100 micelles. The derivatives were successfully separated in 15 min on a C18 analytical column and determined using an integrated derivatization chemiluminescence detection unit based on the bis(2,4,6-trichlorophenyl) oxalate-hydrogen peroxide system. Linear ranges from 3 to 500 microg L(-1), limits of detection at a signal-to-noise ratio of 3 from 0.3 to 0.5 microg L(-1) and relative standard deviations from 2.8 to 4.7% were obtained. The proposed method was applied to the assay of different human urine samples (healthy, smoker and petrol station worker volunteers) and free and total phenol and 4-methylphenol were determined. The proposed method surpasses other chromatographic alternatives for the determination of these phenols in terms of limit of detection and sample requirements for the analysis.

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Phase-Transfer Catalysis in Analytical Chemistry

Starks

Liotta

Halpern³

1994

Phase-Transfer Catalysis

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On-line phase-transfer catalysed dansylation of phenolic compounds followed by normal-phase liquid chromatography with fluorescence detection

Cited by 7 publications

References 4 publications

Derivatization of Ethinylestradiol with Dansyl Chloride To Enhance Electrospray Ionization: Application in Trace Analysis of Ethinylestradiol in Rhesus Monkey Plasma

Derivatization of Ethinylestradiol with Dansyl Chloride To Enhance Electrospray Ionization: Application in Trace Analysis of Ethinylestradiol in Rhesus Monkey Plasma

Sensitive determination of low molecular mass phenols by liquid chromatography with chemiluminescence detection for the determination of phenol and 4-methylphenol in urine

Phase-Transfer Catalysis in Analytical Chemistry

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