Easy determination of benzophenone and its derivatives in sunscreen samples by direct-immersion solid-phase microextraction and gas chromatography-mass spectrometry.

Benzophenones (BPs) absorb different sun radiation wavelengths, making them effective UVA and UVB filters, widely used in industry. In Europe, sunscreen products contain regulated amounts (6 % w/w) of benzophenone-3 (BP-3), usually combined with other filters like octocrylene. BPs are mutagens in UV radiation, and octocrylene may degrade into BPs, making their monitoring crucial. The present manuscript proposed a novel procedure based on liquid-liquid extraction followed by direct-immersion solid-phase microextraction (LLE-DI-SPME) to isolate and determine 10 BPs in sunscreen lotions with potential results. Parameters like extraction solvent, pH, adsorption, desorption time, stirring, sating effect, and presence of organic solvents were optimized and compared with different SPME fibers, being polyacrylate (PA) fiber the most effective. Detection and quantification were performed by gas chromatography-mass-spectrometry. Analytical parameters as limits of detection were 0.05-0.10 µg kg-1, while the linear range was 0.16 up to 2000 µg kg-1. In terms of recovery, the method ranged from 83 % to 103 %; the precision of the method was good in terms of relative standard deviation (RSD) from 3.2 % to 18.7 % and without a remarkable matrix effect (-15.06-8.45 %). Despite the complexity of the samples and the difficulty posed by the DI-SPME technique, the method proved robust. The proposed method successfully detected 10 BPs in 6 different sunscreen lotions. The total presence of BPs in sunscreens ranged from 165 to 931 mg kg-1, with BP-3 detected in all samples from 4.2 to 740 mg kg-1.

Determination of Parabens and Phenolic Compounds in Dairy Products through the Use of a Two-Step Continuous SPE System Including an Enhanced Matrix Removal Sorbent in Combination with UHPLC-MS/MS.

Dairy products can be contaminated by parabens and phenolic compounds from a vast variety of sources, such as packaging and manufacturing processes, or livestock through feed and environmental water. A two-step continuous solid-phase extraction (SPE) and purification methodology was developed here for the determination of both types of compounds. In the first step, a sample extract is passed in sequence through an EMR-lipid sorbent and an Oasis PRiME HBL sorbent to remove fat and preconcentrate the analytes for subsequent detection and quantification by UHPLC-MS/MS. This method enabled the determination of 28 parabens and phenolic contaminant with excellent recovery (91-105%) thanks to the SPE sorbent combination used. The proposed method was validated through the determination of the target compounds, and was found to provide low detection limits (1-20 ng/kg) with only slight matrix effects (0-10%). It was used to analyse 32 different samples of dairy products with different packaging materials. Bisphenol A and bisphenol Z were the two phenolic compounds quantified in the largest number of samples, at concentrations over the range of 24-580 ng/kg, which did not exceed the limit set by European regulations. On the other hand, ethylparaben was the paraben found at the highest levels (33-470 ng/kg).

Trace-Level Determination of Polycyclic Aromatic Hydrocarbons in Dairy Products Available in Spanish Supermarkets by Semi-Automated Solid-Phase Extraction and Gas Chromatography-Mass Spectrometry Detection.

Polycyclic aromatic hydrocarbons (PAHs) have been classified as priority pollutants by the U.S. Environmental Protection Agency (EPA) and the European Commission on the grounds of their carcinogenic, mutagenic and teratogenic properties. Because of their ubiquity in industrial processes and the environment, PAHs can reach milk and dairy products and, eventually, humans. In this work, a new method was developed to detect and quantify sixteen of the EPA's priority PAHs in commercial milk and dairy products. The method involves liquid−liquid extraction (LLE) followed by semi-automated solid-phase extraction (SPE) to clean up and preconcentrate the analytes prior their detection and quantification by gas chromatography−mass spectrometry (GC−MS). The proposed method provided high precision (relative standard deviation < 11.5%), recoveries of 80−107% and low detection limits (1−200 ng/kg). The method was applied to analyze 30 dairy products, the majority of which contained some PAH at concentrations from 7.1 to 1900 ng/kg. The most-detected analytes were the lighter PAHs (naphthalene, acenaphthylene, fluorene and phenanthrene). None of the samples, however, contained more than four PAHs.

Validation and Use of an Accurate, Sensitive Method for Sample Preparation and Gas Chromatography-Mass Spectrometry Determination of Different Endocrine-Disrupting Chemicals in Dairy Products.

Endocrine disrupting chemicals (EDCs) are exogenous substances capable of altering the human hormone system and causing various diseases such as infertility and cancer as a result. In this work, a method for determining twenty-three different EDCs including parabens, alkylphenols, phenylphenols, organophosphorus pesticides, bisphenol A and triclosan in dairy products was developed. Samples are conditioned by addition of acetonitrile containing 1% formic acid, centrifugation and clean-up of the extract by continuous solid-phase extraction. EDCs in the extract are derivatised by heating in a microwave oven and quantified by gas chromatography-mass spectrometry. The proposed method features good limits of detection (6-40 ng/kg) and precision (relative standard deviation < 7.6%); also, it is scarcely subject to matrix effects (1-20%). EDC recoveries from spiked samples ranged from 80 to 108%. The method was used to analyse a total of 33 samples of dairy products including cow, sheep and goat milk, yoghourt, milkshakes, cheese, cream, butter and custard. Bisphenol A was the individual contaminant detected in the greatest number of samples, at concentrations from 180 to 4800 ng/kg. 2-Phenylphenol and ethylparaben were found in more than one-half, at concentrations over the range 130-3500 and 89-4300 ng/kg, respectively. In contrast, alkylphenols, organophosphorus pesticides and triclosan were detected in none.

Use of semi-automated continuous solid-phase extraction and gas chromatography-mass spectrometry for the determination of polycyclic aromatic hydrocarbons in alcoholic and non-alcoholic drinks from Andalucía (Spain).

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) are a large group of contaminants that can reach drinks in various ways. Their assessment in terms of food safety is needed as a priority. The present study developed a methodology to estimate their presence in several types of drinks. RESULTS: In this work, a method was developed for detecting and quantifying PAHs in drinks using a semi-automated, solid-phase extraction closed system for clean up and isolation, and gas chromatography-mass spectrometry (GC-MS) for determination. The proposed method is accurate, precise, and sensitive, with low limits of detection (0.02-0.6 ng L-1 ), low relative standard deviations (< 6.5%), and high recoveries (90-103%). Its high flexibility allows application to a variety of drinks from (Spain) including distillates, beer, wine, cider, soft drinks, fruit juice, tea, and coffee. CONCLUSION: This methodology allows the detection of this family of compounds at trace levels using low quantities of sample and solvents. Most of the samples studied contained two or more of the Environmental Protection Agency's (EPA's) 16 PAH priority pollutants, albeit at levels below the legally allowed limit. © 2018 Society of Chemical Industry.

Determination of free and conjugated forms of endocrine-disrupting chemicals in human biological fluids by GC-MS.

BACKGROUND: Humans are exposed to hazardous substances including endocrine-disrupting chemicals (EDCs). These compounds have been associated with some diseases such as cancer and ascribed adverse effects on life-essential organs. RESULTS: The method, which allows the determination of both free and conjugated forms of EDCs, involves the liquid-liquid extraction from the sample with ethyl acetate, followed by its preconcentration and clean-up by SPE in a continuous system for the subsequent determination by GC-MS. The proposed method affords very low LODs and RSD. CONCLUSION: This allowed its successful application to the determination of EDCs in human urine, blood and breast milk. The most frequently founded were methylparaben, ethylparaben, bisphenol A and triclosan.

Simultaneous determination of parabens, alkylphenols, phenylphenols, bisphenol A and triclosan in human urine, blood and breast milk by continuous solid-phase extraction and gas chromatography-mass spectrometry.

A highly sensitive gas chromatography-mass spectrometry (GC-MS) method for the determination of endocrine disrupting chemicals (EDCs) including parabens, alkylphenols, phenylphenols, bisphenol A and triclosan in human breast milk, blood and urine samples is proposed. Blood and milk require a pretreatment to remove proteins and other substances potentially interfering with the continuous solid-phase extraction (SPE) system used; on the other hand, urine samples can be directly introduced into the system after filtering. Analytes are retained on a LiChrolut EN column and derivatized by silylation following elution with acetonitrile. The resulting trimethylsilyl derivatives are determined by GC-MS. The proposed method exhibited good linearity (r(2)>0.995) for all target EDCs over the concentration range 0.7-10,000ng/l in urine, and 3.3-50,000ng/l in blood and milk. Also, it provided low limits of detection (0.2-1.8ng/l in urine, and 1.0-9.0ng/l in blood and milk), good precision (relative standard deviations less than 7%) and recoveries from 86 to 104%. A total of 24 human fluid samples were analyzed and most found to contain some target EDC at concentrations from 0.10 to 14µg/l.