Analysis of phenolic compounds in health care products by low‐pressure liquid‐chromatography with monolithic column and chemiluminescent detection

Abstract

This paper presents a new application for monolithic columns with low-pressure chromatographic separation using an flow injection analysis configuration with chemiluminescent detection for the determination of a mixture of phenolic compounds: phloroglucinol, 2,4-dihydroxybenzoic acid, salicylic acid, methyl paraben and n-propyl gallate. The procedure consists of the separation of these compounds on a reverse-phase ultra-short monolithic column with pH 3.0 acetate buffer and 5% acetonitrile as carrier phase. The detection is based on a chemiluminescence measurement coming from Ce(IV)-Rhodamine 6G chemistry with the incorporation of two different chemiluminescent chemical conditions in the chromatographic setup in order to enhance the sensitivity for the different phenolic compounds. All separation and detection variables were optimized to propose a determination method. The analysis is performed in 280?s, with the sampling frequency being some 13 h(-1) . The calibration function is a double reciprocal function obtaining good results within two orders of magnitude. The limits of detection were 8.8 × 10 (-8) m (phloroglucinol), 2.7 × 10 (-8) m (2,4-dihydroxybenzoic acid); 2.3 × 10 (-8) m (salicylic acid); 5.2 × 10 (-8) m (methyl paraben) and 4.1 × 10 (-6) m (n-propyl gallate), and the relative standard deviations at a medium level of the linear range were 4.4% (phloroglucinol), 2.8% (2,4-dihydroxybenzoic acid), 5.2% (salicylic acid), 3.6% (methyl paraben) and 6.8% (n-propyl gallate). The method was applied and validated satisfactorily for the determination of these compounds in healthcare products, comparing the results against an HPLC reference method.

Analysis of methylparaben in cosmetics based on a chemiluminescence H2O2−NaIO4−CNQDs system

“…Many analysis methodologies have been proposed for the detection of parabens such as LC–UV, [ 9 ] LC–MS/MS, [ 10,11 ] GC–MS, [ 12 ] electrochemical detection, [ 13 ] and CL detection. [ 14–17 ] Among them, chemiluminescence (CL) was of interest with several advantages of simplicity, sensitivity, and economic efficiency. Cui's group [ 16,17 ] developed a method for the determination of MP, ethylparaben, propylparaben, and butylparaben contents in cosmetic products and foods based on the cerium (IV)‐rhodamine 6G system coupling with LC separation.…”

On-line automated evaluation of lipid nanoparticles transdermal permeation using Franz diffusion cell and low-pressure chromatography

“…For this reason, monolithic columns are suitable to be coupled to low-pressure flow systems, enabling the separation of analytes from matrix components [26][27][28][29][30]. The combination of Flow Injection Analysis (FIA) setups with liquid chromatography using monolithic columns has been applied to determine compounds present in complex matrices such as human urine [31], cosmetic and health care formulations [32,33] and food products [34]. Such associations afforded separation efficiency along with high throughput, manifold versatility and the use of simple low cost equipment.…”

Determination of seven preservatives in cosmetic products by micellar electrokinetic chromatography

“…Preservatives such as alkyl esters of p ‐hydroxybenzoic acids (parabens), phenol, phenoxyethanol and resorcinol are incorporated into various consumer products to prevent or to retard bacterial growth . Parabens, including methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP) and butyl paraben (BP), are the most widely used preservatives in limited concentrations because of their broad antimicrobial activities, relatively low toxicity to humans, good stability, non‐volatility and efficiency over a wide pH range .…”