Search Results (3)

The present study employed a modified QuEChERS method to systematically analyze the presence of fifteen quinolone and seven tetracycline antibiotic residues in local animal food. Additionally, a multi-level four-factor Box–Behnken design (BBD) within the framework of response surface methodology (RSM) was utilized to evaluate the factors impacting the detection efficiency of the sample pretreatment procedure. Optimization was performed via Design Expert^® 10.0.3, and the factors, including the volume of the acetonitrile, the addition of formic acid, the duration of the extraction, and the addition of EDTA, were combined with experimental design until an optimal solution was reached. Finally, the sample was tested via ultra-high performance liquid chromatography-quadrupole-linear ion trap mass spectrometry (UPLC/MS/MS) in both multiple reaction monitoring (MRM) and enhanced product ion (EPI) scan modes on a QTRAP^® 5500 instrument (AB SCIEX instruments, Framingham, MA, USA). The overall average recoveries from actual samples fortified with 22 antibiotics at three levels ranged from 73.8% to 98.5% based on the use of matrix-fortified calibration, with variations ranging from 5.80 to 12.4% (n = 6). The limits of detection and quantification were 0.3 μg kg⁻¹ and 1.0 μg kg⁻¹, respectively. Lastly, the modified method was applied to practical sample analysis in the daily risk monitoring and assessment of food safety with satisfactory stability and robustness. Full article

A method development for determination of neonicotinoid residues in honey samples was developed. The proposed methodology consisted in QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe). That was used for sample preparation and UHPLC/UV (ultra-performance liquid chromatography with ultraviolet detection) utilized for chromatographic analysis. The developed method proved to be sensitive, with LOD (Limit of detection) value in the range of 60.80 to 80.98 ng/g hence LOQ (Limit of quantification) value was in the range of 184.26 to 245.40 ng/g. The method has tested on Polish honey and applied to honey from various countries (Bulgaria, Czech Republic, France, Greece, Italy, Portugal, Romania, Australia, Brazil, Cameroon, Russia, USA and Turkey). Several honey types were tested, while physicochemical properties of all honeys and were investigated. The methodology for general characterization of pollen grains originated from selected plants, to confirm the type of honey was also presented. There was a total lack of the mentioned neonicotinoids in sunflower honey. Except of this, only two samples of rapeseed and two samples of acacia honey (from Poland and Romania) were neonicotinoids free. In 19 samples the targeted pesticides were detected above LOQ. In all other investigated samples, the neonicotinoids were found at least at the LOD or LOQ level. Full article

Fruits and vegetables are considered a good source of antioxidants, which are beneficial in protecting the human body against damage induced by free radicals and other reactive oxygen (ROS) and nitrogen (RNS) species. In this work, we aimed to evaluate the integral antioxidant activity (AOA) and determine individual polyphenols in fruits and vegetables of frequent consumption. For this purpose, an innovative and high throughput analytical approach based on original QuEChERS assisted by ultrasound extraction (USAE), instead of the manual agitation used in the classical procedure, was optimized and implemented for the isolation of polyphenols. The total phenolic content (TPC), flavonoids, anthocyanins, and betalains were evaluated using different spectrophotometric assays. In addition, free radical scavenging by methods 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) were used to estimate the AOA of the investigated fruit and vegetable extracts. Red onion, tamarillo, and beetroot were the samples with the highest AOA. The quantification and identification of free low molecular weight polyphenols from QuEChERS-USAE extracts was carried out by ultra-high-pressure liquid chromatography equipped with a photodiode array detection system (UHPLC-PDA). Catechin was the most abundant polyphenol, followed by gentisic and ferulic acids, mainly in the watercress sample. In relation to flavonols, quercetin and kaempferol were found mostly in onion samples, and in small quantities in tomato and watercress. The improved analytical approach, QuEChERS-USAE/UHPLC-PDA, offers an attractive alternative for the analysis of polyphenols from fruit and vegetable samples, providing several advantages over traditional extraction techniques, in terms of reproducibility, simplicity, low cost, analysis speed, and analytical performance. Full article