Development of a multi-preservative method based on solid-phase microextraction–gas chromatography–tandem mass spectrometry for cosmetic analysis

Mass-Spectrometry-Based Research of Cosmetic Ingredients

Cosmetic products are chemical substances or mixtures used on the skin, hair, nails, teeth, and the mucous membranes of the oral cavity, whose use is intended to clean, protect, correct body odor, perfume, keep in good condition, or change appearance. The analysis of cosmetic ingredients is often challenging because of their huge complexity and their adulteration. Among various analytical tools, mass spectrometry (MS) has been largely used for compound detection, ingredient screening, quality control, detection of product authenticity, and health risk evaluation. This work is focused on the MS applications in detecting and quantification of some common cosmetic ingredients, i.e., preservatives, dyes, heavy metals, allergens, and bioconjugates in various matrices (leave-on or rinse-off cosmetic products). As a global view, MS-based analysis of bioconjugates is a narrow field, and LC- and GC/GC×GC-MS are widely used for the investigation of preservatives, dyes, and fragrances, while inductively coupled plasma (ICP)-MS is ideal for comprehensive analysis of heavy metals. Ambient ionization approaches and advanced separation methods (i.e., convergence chromatography (UPC2)) coupled to MS have been proven to be an excellent choice for the analysis of scented allergens. At the same time, the current paper explores the challenges of MS-based analysis for cosmetic safety studies.

Allergens and Other Harmful Substances in Hydroalcoholic Gels: Compliance with Current Regulation

Hydroalcoholic gels or hand sanitisers have become essential products to prevent and mitigate the transmission of COVID-19. Depending on their use, they can be classified as cosmetics (cleaning the skin) or biocides (with antimicrobial effects). The aim of this work was to determine sixty personal care products frequently found in cosmetic formulations, including fragrance allergens, synthetic musks, preservatives and plasticisers, in hydroalcoholic gels and evaluate their compliance with the current regulation. A simple and fast analytical methodology based on solid-phase microextraction followed by gas chromatography-tandem mass spectrometry (SPME-GC-MS/MS) was validated and applied to 67 real samples. Among the 60 target compounds, 47 of them were found in the analysed hand sanitisers, highlighting the high number of fragrance allergens (up to 23) at concentrations of up to 32,458 μg g-1. Most of the samples did not comply with the labelling requirements of the EU Regulation No 1223/2009, and some of them even contained compounds banned in cosmetic products such as plasticisers. Method sustainability was also evaluated using the metric tool AGREEPrep, demonstrating its greenness.

Migration study of phenolic endocrine disruptors from pacifiers to saliva simulant by solid phase microextraction with amino-functionalized microporous organic network coated fiber

Parabens, bisphenols, and triclosan are used in many baby products, including pacifiers. However, the migration through oral saliva will result in a potential health risk. The present study proposes a sensitive and simple method for the analysis of these chemicals in saliva simulants by solid phase microextraction (SPME) with amino-functionalized microporous organic network (MON-NH₂) coated fiber. The MON-NH₂ showed an excellent adsorption ability for phenolic compounds. The adsorption isotherm fitted the Langmuir isotherm model and the adsorption kinetics followed the pseudo second-order model. The developed SPME method exhibited wide linear ranges (0.005-500 µg/L), good linearity, low limits of quantitation (0.005 µg/L), great recoveries (87.0-112.5 %), and excellent precision (RSD < 8.3 % for intra-day and RSD < 13.7 % for inter-day). Mathematical models based on Fick's second law were applied to predict migration from pacifiers into saliva simulants and a good fit between theoretical and experimental migration results was found. The daily exposure assessment results indicated that these chemicals in pacifiers do not pose unacceptable health risks to infants. However, exposure risks still should be monitored and appropriate precautions are still needed to protect infants from exposure to these chemicals.

A rapid and environmentally friendly method for determination of parabens preservatives in flavors by supercritical fluid chromatography tandem mass spectrometry

A rapid method for determination of parabens preservatives (methyl paraben, ethyl paraben, isopropyl paraben, propyl paraben, isobutyl paraben, and butyl paraben) in flavors was established by using supercritical fluid chromatography tandem mass spectrometry combined with dispersive solid phase extraction. After adding methanol and primary secondary amine to the sample simultaneously, high extraction efficiency and good sample cleanup could be obtained by simple shaking. Parabens were well separated on a Chiralpak IG-3 column in 6 min by gradient elution. Recoveries from spiked blank samples at 0.5, 1.0, and 5.0 mg/kg were determined to be 88.3-106.6%with relative standard deviations less than 8.0%. All analytes achieved good linear relation (r≥0.999 2). The limits of detection for all analytes ranged from 0.03 to 0.09 mg/kg and the limits of quantification from 0.11 to 0.31 mg/kg, respectively. A total of 20 actual samples were successfully analyzed by taking the proposed method. Being simple, rapid, green and reliable, this method can be taken for the determination of parabens preservatives in flavors. This article is protected by copyright. All rights reserved.

Component spectra extraction and quantitative analysis for preservative mixtures by combining terahertz spectroscopy and machine learning

Preservatives are universally used in synergistic combination to enhance antimicrobial effect. Identify compositions and quantify components of preservatives are crucial steps in quality monitoring to guarantee merchandise safety. In the work, three most common preservatives, sorbic acid, potassium sorbate and sodium benzoate, are deliberately mixed in pairs with different mass ratios, which aresupposedto be the "unknown" multicomponent systems and measured by terahertz (THz) time-domain spectroscopy. Subsequently, three major challenges have been accomplished by machine learning methods in this work. The singular value decomposition (SVD) effectively obtains the number of components in mixed preservatives. Then, the component spectra are successfully extracted by non-negative matrix factorization (NMF) and self-modeling mixture analysis (SMMA), which match well with the measured THz spectra of pure reagents. Moreover, the support vector machine for regression (SVR) designed an underlying model to the target components and simultaneously identify contents of each individual component in validation mixtures with decision coefficient R² = 0.989. By taking advantages of the fingerprint-based THz technique and machine learning methods, our approach has been demonstrated the great potential to be served as a useful strategy for detecting preservative mixtures in practical applications.

Trace analysis of multiple synthetic phenolic antioxidants in foods by liquid chromatography-tandem mass spectrometry with complementary use of electrospray ionization and atmospheric pressure chemical ionization

This study presented a universal LC-MS/MS method for trace analysis of multiple synthetic phenolic antioxidants (SPAs) in foods by complementary use of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). The analytes included not only the well-known BHT and BHA but also 18 high molecular weight SPAs. The method utilized APCI to achieve sensitive analysis of BHT, Irganox 1010, Irganox 330, and Irganox 3125 based on the finding that APCI significantly improved the sensitivity of these weakly acidic or slightly polar SPAs, and utilized ESI to obtain sensitive analysis of other SPAs. Additionally, the method avoided background contamination by using effective measures including installation of a trapping column in the LC system. Method performance assessment showed satisfactory sensitivity, linearity, accuracy, and precision for analysis of SPAs in vegetable oil, milk powder, and baby fruit puree. Method application revealed widespread contamination of foods with BHT, Irganox 1010, and Irganox 1076.

Chromium-based metal organic framework for pipette tip micro-solid phase extraction: an effective approach for determination of methyl and propyl parabens in wastewater and shampoo samples

BACKGROUND

A chromium-based metal organic framework was synthesized and employed as an efficient sorbent for pipette tip micro-solid phase extraction and preconcentration of parabens from wastewater and shampoo samples up to sub-ppb level before their spectrophotometric analysis.

RESULTS

Factors affecting preconcentration including volume and type of solvent, amount of sorbent, number of extraction, and volume and pH of samples were optimized employing one-variable-at-a-time and response surface methodology. Obtained analytical characteristics of the method proves its usefulness for analysis of real samples. Linear range of the method for parabens was 1.0-200.0 μg/L. Detection limit of the protocol was 0.24 µg/L for propyl paraben and 0.25 µg/L for methyl paraben. Reproducibility of the protocol defined as % RSD was better than 5.78%. Synthesized adsorbent can be re-used for at least 20 extractions.

CONCLUSION

The method showed a good detection limit and precision for determination of methyl- and propyl-paraben in wastewater and shampoo samples.

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

The use of cosmetics and personal care products is increasing worldwide. Their high matrix complexity, together with the wide range of products currently marketed under different forms imply a challenge for their analysis, most of them requiring a sample pre-treatment step before analysis. Classical sample preparation methodologies involve large amounts of organic solvents as well as multiple steps resulting in large time consumption. Therefore, in recent years, the trends have been moved towards the development of simple, sustainable, and environmentally friendly methodologies in two ways: (i) the miniaturization of conventional procedures allowing a reduction in the consumption of solvents and reagents; and (ii) the development and application of sorbent- and liquid-based microextraction technologies to obtain a high analyte enrichment, avoiding or significantly reducing the use of organic solvents. This review provides an overview of analytical methodology during the last ten years, placing special emphasis on sample preparation to analyse cosmetics and personal care products. The use of liquid–liquid and solid–liquid extraction (LLE, SLE), ultrasound-assisted extraction (UAE), solid-phase extraction (SPE), pressurized liquid extraction (PLE), matrix solid-phase extraction (MSPD), and liquid- and sorbent-based microextraction techniques will be reviewed. The most recent advances and future trends including the development of new materials and green solvents will be also addressed.

Determination of six parabens in biological samples by magnetic solid-phase extraction with magnetic mesoporous carbon adsorbent and UHPLC-MS/MS

Although parabens are useful due to their antiseptic properties, their widespread use has caused concerns regarding their potential toxicological effects. In this study, a novel magnetic solid-phase extraction combined with ultra-high-performance liquid chromatography-tandem mass spectrometry (MSPE-UHPLC-MS/MS) was developed, based on ordered magnetic mesoporous carbon (MMC), for paraben analysis. The MMC was prepared by soft-template synthesis, with a unique pore structure and a highly specific surface response, indicating potential as an excellent adsorbent. Several parameters affecting the paraben extraction efficiency were investigated and a novel method for paraben analysis in serum and urine samples using MSPE-UHPLCMS/MS was developed. The concentrations of methylparaben, ethylparaben, isopropylparaben, and propylparaben in these samples were 0.0380-4.36, 0.460-9.65, 0.0118-0.770, and 0.0363-0.641 μg/L, respectively, whereas isobutylparaben and butylparaben were not detected. Furthermore, satisfactory recoveries of 76.4-121% with relative standard deviations (n = 5) of 1.9-8.6% were obtained. Therefore, the developed MSPE-UHPLC-MS/MS method was efficient, highly sensitive, and reliable for analysing parabens in complex biological samples.

Analytical methods for the determination of endocrine disrupting chemicals in cosmetics and personal care products: A review

Personal care products (PCPs) and cosmetics are indispensable product in our daily routine. Their widespread use makes them a potential route of exposure for certain contaminants to which human would not be normally exposed. One of these contaminants includes endocrine disrupting chemicals, molecules capable of mimicking the body's natural hormones and interfering with the endocrine system. Some of them are ingredients included in the product's formulation, such as UV-filters (sunscreens), phthalates (plasticizers and preservatives), synthetic musks (fragrances), parabens and other antimicrobial agents (antimicrobial preservatives). Others are non-intended added substances that may result from the manufacturing process or migration from the plastic packaging, as with bisphenols and perfluorinated compounds. Some of these endocrine disruptors have been restricted or even banned in cosmetics and PCPs given the high risk they pose to health. Thus, the development of fast, sensitive and precise methods for the identification and quantification of these compounds in cosmetics is a substantial need in order to ensure consumer safety and provide insight into the real risk of human exposure. The present work aims at reviewing the more recently developed analytical methods published in the literature for the determination of endocrine disrupting chemicals in cosmetics and PCPs using chromatographic techniques, with a focus on sample treatment and the quality of analytical parameters.

Solid-phase microextraction-gas chromatography and ultra-high performance liquid chromatography applied to the characterization of lemon wax, a waste product from citrus industry

A novel application of SPME-GC and UHPLC is presented for the elucidation of an unexplored citrus by-product, namely lemon wax. In view of the current environmental protection strategies, directed toward reuse and/or recovery of waste products, this study aimed to evaluate a possible utilization of a discarded fraction from citrus fruits processing. Headspace SPME coupled with GC-MS and GC-FID allowed determining a residual amount (162.25 mg kg^-1) of lemon volatiles, by means of accurate calibration of 38 terpenoids through linear regression analysis (R² = 0.99). SPME method development, was supported by statistical analysis, consisting of experimental design and multisample comparison, where parameters such as type of coating, temperature and time of fiber exposure, were manipulated towards optimization. The optimized method was validated, showing limits of quantification (LOQ) and of detection (LOD) in the ranges 0.24 - 2.65 ng g^-1 and 0.11 - 0.87 ng g^-1, respectively; recoveries ranged from 84.9% to 111.5%. After optimization and validation, the UHPLC-PDA method revealed the presence in lemon wax samples of six coumarins, the most abundant being bergamottin (964 mg kg^-1), followed, in decreasing amount, by citropten, 8-geranyloxypsoralen, biacangelicin, oxypeucedanin, 5-geranyloxy-7-methoxycoumarin; each analyte was calibrated by external standard methodology. Sensitivity (LOD, 31 - 112 ng g^-1; LOQ, 102-370 ng⋅ g^-1), accuracy (recovery, 81-94%), and precision (Retention time RSD, 0.03 - 0.09%; peak area RSD, 1.03-2.92%), were also measured.

A Green and Rapid Analytical Method for the Determination of Hydroxyethoxyphenyl Butanone in Cosmetic Products by Liquid Chromatography

An analytical method for the determination of hydroxyethoxyphenyl butanone, which is used as an alternative preservative in cosmetic products, has been developed and validated for the first time. The method is based on a simple ultrasound-assisted lixiviation of the analyte from the cosmetic matrix followed by liquid chromatography with UV spectrophotometric detection. Under optimized conditions, the method limit of detection and limit of quantification values were 30 and 90 µg·g−1, respectively. The method was validated with good recovery values (86–103%) and precision values (RSD 0.2–4.7%). Finally, the proposed analytical method was successfully applied to 7 commercially available cosmetic samples including both lipophilic and hydrophilic matrices, such as moisturizing cream, sunscreen, shampoo, liquid hand soap, and make-up. Additionally, a laboratory-made cosmetic cream containing the target analyte was prepared and analyzed. The good analytical figures of merit of the proposed method, in addition to its environmentally-friendly characteristics, demonstrate its usefulness to perform the quality control of cosmetic products to ensure the safety of consumers.

Development of an online SPE-UHPLC-MS/MS method for the multiresidue analysis of the 17 compounds from the EU "Watch list"

During the last decades, the quality of aquatic ecosystems has been threatened by increasing levels of pollutions, caused by the discharge of man-made chemicals, both via accidental release of pollutants as well as a consequence of the constant outflow of inadequately treated wastewater effluents. For this reason, the European Union is updating its legislations with the aim of limiting the release of emerging contaminants. The Commission Implementing Decision (EU) 2015/495 published in March 2015 drafts a "Watch list" of compounds to be monitored Europe-wide. In this study, a methodology based on online solid-phase extraction (SPE) ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer (UHPLC-MS/MS) was developed for the simultaneous determination of the 17 compounds listed therein. The proposed method offers advantages over already available methods, such as versatility (all 17 compounds can be analyzed simultaneously), shorter time required for analysis, robustness, and sensitivity. The employment of online sample preparation minimized sample manipulation and reduced dramatically the sample volume needed and time required, dramatically the sample volume needed and time required, thus making the analysis fast and reliable. The method was successfully validated in surface water and influent and effluent wastewater. Limits of detection ranged from sub- to low-nanogram per liter levels, in compliance with the EU limits, with the only exception of EE2. Graphical abstract Schematic of the workflow for the analysis of the Watch list compounds.

Coupling Front-End Separations, Ion Mobility Spectrometry, and Mass Spectrometry For Enhanced Multidimensional Biological and Environmental Analyses

Ion mobility spectrometry (IMS) is a widely used analytical technique for rapid molecular separations in the gas phase. Though IMS alone is useful, its coupling with mass spectrometry (MS) and front-end separations is extremely beneficial for increasing measurement sensitivity, peak capacity of complex mixtures, and the scope of molecular information available from biological and environmental sample analyses. In fact, multiple disease screening and environmental evaluations have illustrated that the IMS-based multidimensional separations extract information that cannot be acquired with each technique individually. This review highlights three-dimensional separations using IMS-MS in conjunction with a range of front-end techniques, such as gas chromatography, supercritical fluid chromatography, liquid chromatography, solid-phase extractions, capillary electrophoresis, field asymmetric ion mobility spectrometry, and microfluidic devices. The origination, current state, various applications, and future capabilities of these multidimensional approaches are described in detail to provide insight into their uses and benefits.

Simultaneous in-vial acetylation solid-phase microextraction followed by gas chromatography tandem mass spectrometry for the analysis of multiclass organic UV filters in water

UV filters are a class of emerging contaminants that are widely used in personal care products (PCPs) and that can be detected at low concentrations in the aquatic environment (ngL^-1). Sensitive modern analytical methods are then mandatory to accurately analyze them. A methodology based on solid-phase-microextraction (SPME), considered as a 'Green Chemistry' technique, followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous analysis of 14 UV filters of different chemical nature in environmental and recreational waters. In-vial low-cost derivatization was carried out to improve chromatographic performance of phenolic compounds. The extraction parameters (fiber coating, extraction mode, and salt addition) were optimized by means of experimental designs in order to achieve reliable conditions. Finally, the SPME-GC-MS/MS method was validated in terms of linearity, accuracy and precision with LODs in the low ngL^-1 level. Its application to the analysis of 28 different samples including sea, river, spa, swimming pool, and aquapark waters, enabled the detection of 11 target UV filters at concentration levels up to 540μgL^-1, highlighting the presence of OCR in all analyzed samples and of 2EHMC (proposed to be considered as priority pollutant) in 79% of them.

Direct identification of prohibited substances in cosmetics and foodstuffs using ambient ionization on a miniature mass spectrometry system

Significantly simplified work flows were developed for rapid analysis of various types of cosmetic and foodstuff samples by employing a miniature mass spectrometry system and ambient ionization methods. A desktop Mini 12 ion trap mass spectrometer was coupled with paper spray ionization, extraction spray ionization and slug-flow microextraction for direct analysis of Sudan Reds, parabens, antibiotics, steroids, bisphenol and plasticizer from raw samples with complex matrices. Limits of detection as low as 5 μg/kg were obtained for target analytes. On-line derivatization was also implemented for analysis of steroid in cosmetics. The developed methods provide potential analytical possibility for outside-the-lab screening of cosmetics and foodstuff products for the presence of illegal substances.

Positive lists of cosmetic ingredients: Analytical methodology for regulatory and safety controls - A review

Cosmetic products placed on the market and their ingredients, must be safe under reasonable conditions of use, in accordance to the current legislation. Therefore, regulated and allowed chemical substances must meet the regulatory criteria to be used as ingredients in cosmetics and personal care products, and adequate analytical methodology is needed to evaluate the degree of compliance. This article reviews the most recent methods (2005-2015) used for the extraction and the analytical determination of the ingredients included in the positive lists of the European Regulation of Cosmetic Products (EC 1223/2009): comprising colorants, preservatives and UV filters. It summarizes the analytical properties of the most relevant analytical methods along with the possibilities of fulfilment of the current regulatory issues. The cosmetic legislation is frequently being updated; consequently, the analytical methodology must be constantly revised and improved to meet safety requirements. The article highlights the most important advances in analytical methodology for cosmetics control, both in relation to the sample pretreatment and extraction and the different instrumental approaches developed to solve this challenge. Cosmetics are complex samples, and most of them require a sample pretreatment before analysis. In the last times, the research conducted covering this aspect, tended to the use of green extraction and microextraction techniques. Analytical methods were generally based on liquid chromatography with UV detection, and gas and liquid chromatographic techniques hyphenated with single or tandem mass spectrometry; but some interesting proposals based on electrophoresis have also been reported, together with some electroanalytical approaches. Regarding the number of ingredients considered for analytical control, single analyte methods have been proposed, although the most useful ones in the real life cosmetic analysis are the multianalyte approaches.

Simultaneous determination of multiclass preservatives including isothiazolinones and benzophenone-type UV filters in household and personal care products by micellar electrokinetic chromatography

In this work, a simple and reliable micellar electrokinetic chromatography method for the separation and quantification of 14 preservatives, including isothiazolinones, and two benzophenone-type UV filters in household, cosmetic and personal care products was developed. The selected priority compounds are widely used as ingredients in many personal care products, and are included in the European Regulation concerning cosmetic products. The electrophoretic separation parameters were optimized by means of a modified chromatographic response function in combination with an experimental design, namely a central composite design. After optimization of experimental conditions, the BGE selected for the separation of the targets consisted of 60 mM SDS, 18 mM sodium tetraborate, pH 9.4 and 10% v/v methanol. The MEKC method was checked in terms of linearity, LODs and quantification, repeatability, intermediate precision, and accuracy, providing appropriate values (i.e. R(2) ≥ 0.992, repeatability RSD values ˂9%, and accuracy 90-115%). Applicability of the validated method was successfully assessed by quantifying preservatives and UV filters in commercial consumer products.