Determination of N‐nitrosamines in cosmetic products by vortex‐assisted reversed‐phase dispersive liquid–liquid microextraction and liquid chromatography with mass spectrometry

Abstract

A new analytical method for the simultaneous determination of trace levels of seven prohibited N-nitrosamines (N-nitrosodimethylamine, N-nitrosoethylmethylamine, N-nitrosopyrrolidine, N-nitrosodiethylamine, N-nitrosopiperidine, N-nitrosomorpholine, and N-nitrosodiethanolamine) in cosmetic products has been developed. The method is based on vortex-assisted reversed-phase dispersive liquid-liquid microextraction, which allows the extraction of highly polar compounds, followed by liquid chromatography with mass spectrometry. The variables involved in the extraction process were studied to obtain the highest enrichment factor. Under the selected conditions, 75 μL of water as extraction solvent was added to 5 mL of n-hexane sample solution and assisted by vortex mixing during 30 s to form the cloudy solution. The method was successfully validated showing good linearity (0.5-50 ng/mL), enrichment factors up to 65 depending on the target compound, limits of detection values of 1.8-50 ng/g, and good repeatability (RSD < 9.8%). Finally, the proposed method was applied to different cosmetic samples. Quantitative relative recovery values (80-113%) were obtained, thus showing that matrix effects were negligible. The achieved analytical features of the proposed method, besides of its simplicity and affordability, make it useful to perform the quality control of cosmetic products to ensure the safety of consumers.

Recent Advances in Sample Preparation for Cosmetics and Personal Care Products Analysis

“…One decade ago, Hashemi et al [ 141 ] proposed a modification of the original DLLME called reversed-phase DLLME (RP-DLLME), where a small volume of water, used as extraction solvent, is dispersed into a bulk organic solution containing the polar target analytes. RP-DLLME has recently been applied to extract n-nitrosamines [ 115 , 116 ] and free formaldehyde [ 117 ] from cosmetics and personal care products before LC-MS [ 115 ] or HPLC-UV analysis [ 116 , 117 ]. In all cases, the employed volume of water ranged between 50 and 125 µL, with recoveries and LODs similar to those obtained for the analysis of free formaldehyde by UAE-CPE-UV-Vis [ 40 ] or n-nitrosamines employing SPE-LC-MS/MS [ 44 ].…”

Preparation of flower‐like molybdenum disulfide for solid‐phase extraction of N‐nitrosoamines in environmental water samples

“…Thus, pre-concentration and purification are necessary before NAs are detected. The commonly used pretreatment techniques for NAs mainly include liquidliquid extraction [8] and SPE [9,10]. Compared with liquidliquid extraction, SPE possesses advantages of easy operation, high enrichment factors, effectively removing interferences, and reducing consumption of organic solvents [11].…”

Combining ultrasound‐assisted extraction and vortex‐assisted liquid–liquid microextraction for the sensitive assessment of aflatoxins in aquaculture fish species

“…On other occasions, the extraction solvent dispersion is achieved by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent repeatedly in a glass syringe (air‐assisted dispersive liquid–liquid microextraction) . DLLME extractive capabilities can be also increased by fast shaking using a vortex (vortex‐assisted liquid–liquid microextraction [VALLME]), which leads to a fast extracting solving dispersion and a fast mass transfer from the aqueous phase to the organic extractant . Advantages of VALLME are mainly the low price of the shaking device (vortex are widely available) in comparison to ultrasound and microwaves apparatus.…”