New developments in the extraction and determination of parabens in cosmetics and environmental samples. A review

3D-Printed Microflow Injection Analysis Platform for Online Magnetic Nanoparticle Sorptive Extraction of Antimicrobials in Biological Specimens as a Front End to Liquid Chromatographic Assays

In this work, the concept of 3D-printed microflow injection (3D-μFI) embodying a dedicated multifunctional 3D-printed stator onto a rotary microvalve along with a mesofluidic sample preparation platform is proposed for the first time. A transparent 3D-printed stereolithographic mesofluidic chip device accommodating polyaniline (PANI) decorated magnetic nanoparticles (32.5 ± 3.8 mg) is harnessed to in-line sorptive microextraction as a front end to liquid chromatography with peak focusing. As a proof-of-concept application, the 3D-μFI assembly was resorted to matrix cleanup and automatic programmable-flow determination of organic emerging contaminants (4-hydroxybenzoate analogues and triclosan as antimicrobial model analytes) in human saliva and urine samples. By using a sample volume of 1.0 mL with a loading flow rate of 200 μL min^-1, an eluent volume of 120 μL at 80 μL min^-1, and online HPLC injection of 300 μL of the mixture of eluate and Milli-Q water (in a 1:2 ratio) to prevent band broadening effects of the most polar analytes, the limits of detection (3σ criterion) ranged from 1.1 to 4.5 ng mL^-1 for methylparaben (MP), ethylparaben (EP), propylparaben (PrP), phenylparaben (PhP), butylparaben (BP), and triclosan (TCS). Enhancement factors of 16-25 were obtained for the target analytes. Spike recoveries ranged from 84 to 117% for both saliva and urine samples. The online 3D-μFI hyphenated method is synchronized with the chromatographic separation and features a chip lifetime of more than 20 injections with minimal losses of moderately nonpolar compounds on the walls of the mesofluidic device.

Rapid and sensitive determination of multiple endocrine-disrupting chemicals by ultrasound-assisted in situ derivatization dispersive liquid-liquid microextraction coupled with ultra-high-performance liquid chromatography/tandem mass spectrometry

RATIONALE

Endocrine-disrupting chemicals (EDCs) in environment samples and food stuffs are an increasing serious public health issue due to their potency to interfere and deregulate several aspects of the endocrine system. Because of their extremely low abundance, it remains a challenging task to develop a sensitive detection method.

METHODS

4'-Carbonyl chloride rosamine (CCR) was used as a derivatization reagent for EDCs for the first time. A new ultrasound-assisted in situ derivatization/dispersive liquid-liquid microextraction (UA-DLLME with in situ derivatization) method for multiple EDCs including five estrogens, two alkylphenols, eight bisphenols, seven parabens and triclosan coupled with ultra-high-performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) has been developed and validated.

RESULTS

The ionization efficiency of EDCs was greatly enhanced through the introduction of a permanent charged moiety of CCR into the derivatives during electrospray ionization (ESI)-MS analysis. The main variables potentially affecting the UA-DLLME with in situ derivatization process are optimized. The recoveries and matrix effects of 23 EDCs for the spiking samples were in the range of 83.0-116.0% and 85.8-114.6%, respectively. Good method reproducibility was achieved.

CONCLUSIONS

The limits of detection (LODs) for 23 EDCs were 0.05-0.40 ng/L and 0.03-0.25 ng/g (dry weight, d.w.) for environment samples and food stuffs, respectively. The proposed method has been demonstrated to be suitable for simultaneous determination of multiple EDCs in real samples with high sensitivity, speediness, and good sample clean-up ability. Copyright © 2017 John Wiley & Sons, Ltd.

Measuring biomarkers in wastewater as a new source of epidemiological information: Current state and future perspectives

The information obtained from the chemical analysis of specific human excretion products (biomarkers) in urban wastewater can be used to estimate the exposure or consumption of the population under investigation to a defined substance. A proper biomarker can provide relevant information about lifestyle habits, health and wellbeing, but its selection is not an easy task as it should fulfil several specific requirements in order to be successfully employed. This paper aims to summarize the current knowledge related to the most relevant biomarkers used so far. In addition, some potential wastewater biomarkers that could be used for future applications were evaluated. For this purpose, representative chemical classes have been chosen and grouped in four main categories: (i) those that provide estimates of lifestyle factors and substance use, (ii) those used to estimate the exposure to toxicants present in the environment and food, (iii) those that have the potential to provide information about public health and illness and (iv) those used to estimate the population size. To facilitate the evaluation of the eligibility of a compound as a biomarker, information, when available, on stability in urine and wastewater and pharmacokinetic data (i.e. metabolism and urinary excretion profile) has been reviewed. Finally, several needs and recommendations for future research are proposed.

A derivatization-enhanced detection strategy in mass spectrometry: analysis of 4-hydroxybenzoates and their metabolites after keratinocytes are exposed to UV radiation

4-Hydroxybenzoate is a phenolic derivative of alkyl benzoates and is a widely used preservative in cosmetic and pharmaceutical products. The presence of 4-hydroxybenzoates in the human body may result from the use of pharmaceutical and personal care products. These compounds are also known to exhibit estrogenic and genotoxic activities. The potential adverse effects of these compounds include endocrine disruption, oxidative and DNA damage, contact dermatitis, and allergic reactions. This study used two mass spectrometry methods that are applicable when using a derivatization-enhanced detection strategy (DEDS) to screen 4-hydroxybenzoates and their metabolites. Chemical derivatization was used to enhance the detection of these compounds. To evaluate the metabolic process triggered by UV radiation, human keratinocyte HaCaT cells treated with these 4-hydroxybenzoates were further exposed to UVA, UVB and UVC radiation. Metabolites transformed by human keratinocytes in the chemical derivatization procedure were identified by a nano ultra-performance liquid chromatographic system (nanoUPLC) coupled with LTQ Orbitrap. The experiments confirmed the feasibility of this method for identifying 4-hydroxybenzoate metabolites and for high-throughput screening of 4-hydroxybenzoate in commercial products (50 samples) by the DEDS.

An ionic liquid loaded magnetically confined polymeric mesoporous adsorbent for extraction of parabens from environmental and cosmetic samples

Schematic illustration of MSPE procedure for paraben analysis using a new ionic liquid loaded magnetically confined polymeric mesoporous material.

Current trends in sample preparation for cosmetic analysis

The widespread applications of cosmetics in modern life make their analysis particularly important from a safety point of view. There is a wide variety of restricted ingredients and prohibited substances that primarily influence the safety of cosmetics. Sample preparation for cosmetic analysis is a crucial step as the complex matrices may seriously interfere with the determination of target analytes. In this review, some new developments (2010-2016) in sample preparation techniques for cosmetic analysis, including liquid-phase microextraction, solid-phase microextraction, matrix solid-phase dispersion, pressurized liquid extraction, cloud point extraction, ultrasound-assisted extraction, and microwave digestion, are presented. Furthermore, the research and progress in sample preparation techniques and their applications in the separation and purification of allowed ingredients and prohibited substances are reviewed.

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.

Gas Chromatographic determination of parabens after derivatization and dispersive microextraction

In this study a dispersive liquid–liquid microextraction method combines with an in situ derivatization. The proposed method is used for the extraction and pre-concentration of some preservatives including methyl paraben, ethyl paraben, propyl paraben and butyl paraben from different water matrices. The extracted compounds are monitored by gas chromatography-flame ionization detector. Parabens are derivatizated by propionic anhydride. The effects of the extraction solvent type, extraction and acylation time, derivative agent volume, temperature, pH and the ionic strength of the solution on the extraction efficiency were investigated. 50 mkl chloroform and 500 mkl acetonitrile is a mixture of suitable extraction and dispersive solvents. The mixture is centrifuged for 3min at 4000 rpm. 20 mkl propionic anhydride is used for derivatization parabens in the concentration range of 0.05 - 1 mg within 2 - 3 minutes. The optimum pH range is 8 - 9. The relative standard deviations (RSDs) of parabens were in the range of 2.0–10.0% (n = 3). The method was applied to the analysis of the four parabens in water. For the analysis of the spiked samples, a recovery above 100 % were obtained.