Neutral desorption extractive electrospray ionization mass spectrometry for fast screening sunscreen agents in cream cosmetic products

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.

Applications of mass spectrometry in cosmetic analysis: An overview

Mass spectrometry (MS) is a crucial tool in cosmetic analysis. It is widely used for ingredient screening, quality control, risk monitoring, authenticity verification, and efficacy evaluation. However, due to the diversity of cosmetic products and the rapid development of MS-based analytical methods, the relevant literature needs a more systematic collation of information on this subject to unravel the true potential of MS in cosmetic analysis. Herein, an overview of the role of MS in cosmetic analysis over the past two decades is presented. The currently used sample preparation methods, ionization techniques, and types of mass analyzers are demonstrated in detail. In addition, a brief perspective on the future development of MS for cosmetic analysis is provided.

[Determination of 13 sunscreen agents in cosmetics by gas chromatography-mass spectrometry]

Sunscreens can be categorized as physical and chemical types. Chemical sunscreens are widely used in cosmetics, and hence, their concentration in the desired products should be strictly monitored. Gas chromatography-mass spectrometry (GC-MS) is widely used for the analysis of cosmetics as it does not require organic mobile phases and allows for accurate qualitative and quantitative analyses. In this study, a method based on GC-MS was established for the determination of 13 sunscreen agents in cosmetics: ethylhexyl salicylate, homosalate, 4-methylbenzylidene camphor, ethylhexyl dimethyl para-aminobenzoic acid, ethylhexyl methoxycinnamate, octocrylene, butyl methoxydibenzoylmethane, diethylamino hydroxybenzoyl hexyl benzoate, 3-benzylidene camphor, benzophenone-3, camphor benzalkonium methosulfate, drometrizole trisiloxane, and isopentyl-4-methoxycinnamate. Accordingly, 0.5 g of the cosmetic product was dissolved in dichloromethane in a 50 mL volumetric flask and extracted ultrasonically for 15 min. Then, 1.0 mL of the extracting solution was withdrawn and diluted to 50.0 mL with dichloromethane. The mixture was filtered through a 0.22-μm membrane. A 1 μL aliquot of the dichloromethane solution was introduced onto the HP-5ms chromatographic column (30 m×250 μm×0.25 μm). The 13 components were separated under programed temperature elevation in the interval from 150 ℃ to 290 ℃. These components could be analyzed within 30 min after being ionized by the EI source, and their determination was achieved in selected ion monitoring (SIM) mode. The external standard method was employed for quantitative determination. Linear equations, linear correlation coefficients, and linear ranges were obtained by analyzing a series of mixed standard working solutions. The limits of detection (LODs, S/N=3) and limits of quantification (LOQs, S/N=10) of the 13 sunscreen agents were determined. The matrix effect and average recoveries of the 13 agents with six extraction solvents (dichloromethane, tetrahydrofuran, methanol, acetonitrile, n-hexane, and acetone) were compared. Among these, dichloromethane showed a weak matrix effect and high average recovery. The matrix effect of dichloromethane was 90.1%-100.5%, and the average recovery was 96.3%. All the 13 sunscreen agents showed good linearity in their corresponding ranges. The correlation coefficients (r 2) were higher than 0.998. The LODs and LOQs were in the ranges of 0.04 to 0.63 mg/g and 0.12 to 2.10 mg/g, respectively. Two types of cosmetics were selected to verify the accuracy and precision of the method at three levels. The average spiked recoveries of the 13 sunscreen agents in cream and lotion were 88.7%-103.6%, and 88.4%-102.3%, respectively; the corresponding relative standard deviations (RSDs, n=6) were 1.7%-4.9% and 1.2%-3.9%. Whitening cosmetics are frequently added with sunscreen agents, which is a regulatory blind spot. Five batches of skin whitening products containing sunscreen agents were detected using this method. The contents of five sunscreen agents in skin whitening cosmetics ranged from 0.8% to 5.2%, which were lower than the relevant limits in China. Owing to its advantages of simple operation, high sensitivity, and good recovery, the proposed method is suitable for the qualitative and quantitative determination of 13 sunscreen agents in cosmetics. This method provides technical support for market supervision and laboratory testing.

Neutral Desorption Extractive Electrospray Ionization Mass Spectrometry Analysis Sputum for Non-Invasive Lung Adenocarcinoma Detection

Purpose

Increased use of low-dose spiral computed tomography (LDCT: low-dose computed tomography) screening has contributed to more frequent incidental detection of peripheral lung nodules, part of them were adenocarcinoma, which need to be further evaluated to establish a definitive diagnosis. Here, our primary objective was to evaluate the ambient mass spectrometry (AMS) sputum analysis as a non-invasive lung adenocarcinoma (LAC) diagnosis solution.

Patients and Methods

Neutral desorption extractive electrospray ionization mass spectrometry (ND-EESI-MS) and collision induced dissociation (CID) were used to detect sputum metabolites from 143 spontaneous sputum samples. Partial least squares-discriminant analysis (PLS-DA) was used to refine the biomarker panel, whereas orthogonal PLS-DA (OPLS-DA) was used to operationalize the enhanced biomarker panel for diagnosis.

Results

In this approach, 19 altered metabolites were detected by ND-EESI-MS from 76 cases of LAC and 67 cases of control. Significance testing and receiver operating characteristic (ROC) analysis identified 5 metabolites [hydroxyphenyllactic acid, phytosphingosine, N-nonanoylglycine, sphinganine, S-carboxymethyl-L-cysteine] with p <0.05 and AUC >0.75, respectively. Evaluation of model performance for prediction of LAC resulted in a cross-validation classification accuracy of 87.9%. Metabolic pathway analysis showed that sphingolipid metabolism, fatty acid metabolism, carnitine synthesis and Warburg effect were most impacted in response to disease.

Conclusion

This study indicates that the application of ND-EESI-MS to sputum analysis can be used as a non-invasive detection of peripheral lung nodules. The use of sputum metabolite biomarkers may aid in the development of a further evaluation program for lung adenocarcinoma.

Using thermal desorption electrospray ionization mass spectrometry to rapidly determine antimicrobial preservatives in cosmetics

RATIONALE

Characterization and quantification of permitted preservatives are important inspections to prevent the overuse of preservatives in authentic formulations. However, the complexity of sample matrices makes preservative determination in cosmetics a tedious process. A rapid analytical strategy to identify preservatives would insure large numbers of products are in compliance with government regulations.

METHODS

Thermal desorption electrospray ionization mass spectrometry (TD-ESI-MS) was used to directly detect preservative compounds in authentic formulations without sample pretreatment. The technique employs a metal probe, which was configured for sampling cosmetics in their original states and was inserted in a closed preheated oven to thermally desorb analytes. The desorbed analytes were then carried by a nitrogen gas stream into an ESI plume, where the formed ions were subsequently detected by the mass analyzer.

RESULTS

The TD-ESI mass and tandem mass spectra of different classes of preservative standards were rapidly obtained, and the limits of detection were far below the legal limit of their respective concentrations. The preservatives were also directly detected in different types of authentic formulations in the absence of sample preparation, and within a few seconds per sample. Calibration curves for preservatives in four common formulations yielded good linearity in the regulation-allowed range.

CONCLUSIONS

Due to its sensitivity, short analysis time, repeatability, and quantitative ability, TD-ESI-MS may serve as a suitable tool for large-scale screening of cosmetic preservatives to assure product safety. Copyright © 2016 John Wiley & Sons, Ltd.

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.

Secondary Electrospray Ionization

This chapter details the technique called extractive electrospray ionization (EESI) and describes its state-of-the-art developmental, mechanical and experimental aspects and shows its most important applications. EESI is a sensitive, matrix-tolerant secondary electrospray ionization technique, which is in the focus of ongoing investigations. The strength of EESI is its ability to ionize various compounds directly out of the sample without preparation or chromatographic separation. Although it appears to be not always the most sensitive method, it has shown enormous capabilities for various applications such as breath or skin analysis, the classification of perfumes, detection of melamine in milk and identification of the freshness of frozen meat or fruit.