Simultaneous determination of ten preservatives in ten kinds of foods by micellar electrokinetic chromatography

Preparation and application of an imidazolium-based poly (ionic liquid) functionalized silica sorbent for solid-phase extraction of parabens from food samples

In this work, an imidazolium-based poly (ionic liquid) (poly(1-octyl-3-vinyl- imidazolium naphthalene sulfonate)) functionalized silica (poly(C8VIm+NapSO3-) @SiO2) was successfully prepared for the determination of parabens in food samples. The prepared poly(C8VIm+NapSO3-)@SiO2 was characterized by Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectrogram (XPS) and Scanning electron microscopy (SEM). The simulation calculation results indicated that the suitable binding energies were between the polymeric ionic liquids and parabens, and the main interactions for extraction were hydrogen bonding, electrostatic and π-π stacking interactions. In addition, compared with commercial extraction materials, the prepared poly(C8VIm+NapSO3-)@SiO2 sorbent showed comparable or even better extraction performance towards parabens. The effective parameters were optimized by a combination of the univariate method and Box-Behnken design (BBD). Under the optimum conditions, coupled with high performance liquid chromatography (HPLC), wide linear ranges (1.0-800 μg L-1), good linearity (R2 ≥ 0.9997) and low limits of detection (0.1 μg L-1) were obtained. In addition, the intra-day and inter-day relative standard deviations (RSDs) were all lower than 6.3%. Moreover, the proposed method was successfully used for the determination of parabens in food samples and satisfactory recoveries in the range of 76.9-97.4% were obtained. The results indicated that the proposed method had good sensitivity, accuracy and precision for the detection of parabens in food samples.

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.

Review: Microextraction Technique Based New Trends in Food Analysis

Food chemistry is the study and classification of the quality and origin of foods. The identification of definite biomarkers and the determination of residue contaminants such as toxins, pesticides, metals, human and veterinary drugs, which are a very common source of food-borne diseases. The food analysis is continuously demanding the improvement of more robust, sensitive, highly efficient, and economically beneficial analytical approaches to promise the traceability, safety, and quality of foods in the acquiescence with the consumers and legislation demands. The traditional methods have been used at the starting of the 20th century based on wet chemical methods. Now it existing the powerful analytical techniques used in food analysis and safety. This development has led to substantial enhancements in the analytical accuracy, precision, sensitivity, selectivity, thereby mounting the applied range of food applications. In the present decade, microextraction (micro-scale extraction) pays more attention due to its futures such as low consumption of solvent and sample, throughput analysis easy to operate, greener, robotics, and miniaturization, different adsorbents have been used in the microextraction process with unique nature recognized with wide range applications.

Development and Validation of HPLC-DAD Method for Simultaneous Determination of Seven Food Additives and Caffeine in Powdered Drinks

The usage of food additives must respect the general legislation in force in the country and requires a reliable analytical method for surveillance. This research aimed to develop a high-performance liquid chromatography with diode array detection (HPLC-DAD) method for the simultaneous determination of seven food additives and caffeine in powdered drinks. Three factors likely to affect the chromatographic separation, namely, mobile phase composition at the beginning (x₁, 0–10% of the amount of methanol in the phosphate buffer) and the end (x₂, 60–100% of the amount of methanol in the phosphate buffer) of the gradient program and pH (x₃, 3–7), were evaluated with the aid of a Box–Behnken Design (BBD). Subsequently, multi-response optimizations for chromatographic resolutions (Rs) and analysis time were performed using the response surface methodology (RSM) in conjunction with the desirability function (DF). Complete separation (Rs > 1.5) of seven food additives and caffeine was achieved in less than 16 min by applying 8.5% methanol in the phosphate buffer at the beginning and 90% at the end of the gradient program, in pH 6.7. The developed method was validated with low limits of detection (ranging from 1.16 mg kg⁻¹ (sodium saccharin) to 3.00 mg kg⁻¹ (acesulfame potassium)), low limits of quantification (ranging from 3.86 mg kg⁻¹ (sodium saccharin) to 10.02 mg kg⁻¹ (acesulfame potassium)), high precision (CV < 4%), and high accuracy (recoveries from 95 to 101% at 80, 100, and 120% of the target concentration). The method was successfully used to assess the seven food additives and caffeine in commercially available powdered drinks.

Assessment of Microbiological and Chemical Quality of Bubble Tea Beverages Vended in Taiwan

Bubble tea beverages (n = 105) purchased from vendors in Taiwan were tested to determine their microbiological and chemical quality. Nearly half of the tested samples (48.6%, 51 of 105) had aerobic plate counts (APCs) higher than the Taiwan Food and Drug Administration guideline of 4.0 log CFU/mL, and 55 (52.4%) had coliform counts (most probable number [MPN]) higher than the 10 MPN/mL guideline. Escherichia coli, Salmonella, Staphylococcus aureus, sweeteners, preservatives, maleic acid, and coumarin were not detected in any sample. However, catechins were not detected to 188 mg/mL, and caffeine was 10.1 to 457.6 mg/mL. Bubble tea samples obtained from vendors in southern Taiwan had a mean APC of 2.6 log CFU/mL and a mean coliform count of 61.7 MPN/mL; these values were significantly lower (P < 0.05) than those from samples collected from vendors in northern, eastern, or central Taiwan. Samples obtained from southern Taiwan had the highest mean catechin concentrations of 21.3 mg/mL (P < 0.05). About 60% (63 of 105) of the bubble tea samples were not labeled with the origin of the tea leaves, which is in violation of Taiwanese food labeling regulations. In general, the bubble tea beverages tested had satisfactory microbial and chemical qualities.

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

This review work presents and discusses the main applications of capillary electromigration methods in food analysis and Foodomics. Papers that were published during the period February 2015-February 2017 are included following the previous review by Acunha et al. (Electrophoresis 2016, 37, 111-141). The paper shows the large variety of food related molecules that have been analyzed by CE including amino acids, biogenic amines, carbohydrates, chiral compounds, contaminants, DNAs, food additives, heterocyclic amines, lipids, peptides, pesticides, phenols, pigments, polyphenols, proteins, residues, toxins, vitamins, small organic and inorganic compounds, as well as other minor compounds. This work describes the last results on food quality and safety, nutritional value, storage, bioactivity, as well as uses of CE for monitoring food interactions and food processing including recent microchips developments and new applications of CE in Foodomics.