Magnet integrated fabric phase sorptive extraction as a stand-alone extraction device for the monitoring of benzoyl urea insecticides in water samples by HPLC-DAD.

Benzoyl urea insecticides are a class of pesticides used in agriculture for the inhibition of chitin synthesis in pests. These compounds are persistent in environmental samples, and thus their monitoring is necessary to avoid detrimental effects to human health and the environment. Magnet integrated fabric phase sorptive extraction (MI-FPSE) is a recently introduced sample preparation technique that combines sample stirring and analyte extraction into one stand-alone device. However, the applicability and the potential benefits of this technique in environmental analysis remain unexplored. In the present study, MI-FPSE was employed for the first time for the extraction and preconcentration of benzoyl urea insecticides (i.e., diflubenzuron, triflumuron, hexaflumuron, lufenuron and chlorfluazuron) from environmental water samples prior to their determination by high performance liquid chromatography-diode array detection (HPLC-DAD). The main factors affecting the performance of the proposed methodology were thoroughly investigated and optimized and the MI-FPSE-HPLC-DAD method was validated. The proposed method enabled the handling of relatively high sample quantity resulting in high preconcentration factors (501 and 731) and good sensitivity. Under optimum conditions, the limits of detection and the limits of quantification for the benzoyl urea insecticides were 0.06 ng mL-1 and 0.20 ng mL-1, respectively. Moreover, the relative standard deviations were less than 6.1% for intra-day study and less than 8.2% for inter-day study showing good method precision. After its validation, the herein developed method was successfully employed for the analysis of tap, mineral, river, and lake water samples. In addition, the ComplexGAPI index was used to present the green potential of developed method from the step of MI-FPSE device preparation to final determination. All things considered, MI-FPSE could potentially serve as an efficient tool for the monitoring of pollutants in environmental analysis.

Exploring sol-gel zwitterionic fabric phase sorptive extraction sorbent as a new multi-mode platform for the extraction and preconcentration of triazine herbicides from juice samples.

Triazine herbicides are a class of common pesticides which are widely used to control the weeds in many agricultural crops. Although many studies have described methodologies for the determination of triazine herbicides in aqueous samples, the attention given to agricultural crops and their products is far more limited. In this study, a novel sol-gel zwitterionic multi-mode fabric phase sorptive extraction (FPSE) platform was developed for the matrix clean-up, extraction and preconcentration of five triazine herbicides from fruit juice samples prior to their determination by high performance liquid chromatography-diode array detection (HPLC-DAD). The novel zwitterionic multi-mode sorbent was characterized and its performance for fruit juice analysis was evaluated. Compared to other sol-gel sorbents, the novel zwitterionic sorbent helped cleaning all the acidic interferences from fruit juices. The herein reported FPSE protocol was optimized and validated. Under optimum conditions, the FPSE method showed good accuracy, precision and sensitivity. The limits of detection and limits of quantification for all analytes were 0.15 ng mL-1 and 0.50 ng mL-1, respectively. The enhancement factors of this method ranged between 36.7 and 51.8. The relative standard deviation for intra-day precision was below 5.6% and for inter-day precision was below 8.8%. Finally, the proposed FPSE-HPLC-DAD method was successfully employed for the analysis of various fruit juice samples.

Magnet integrated fabric phase sorptive extraction of selected endocrine disrupting chemicals from human urine followed by high-performance liquid chromatography - photodiode array analysis.

In current paper, a new advanced modification of fabric phase sorptive extraction is introduced for the first time. This advantageous configuration that integrates the stirring and extraction mechanism into a single sample preparation device was originated by equally considering the beneficial role of the increase of extraction kinetics and more specifically of diffusion on the extraction efficiency of the equilibrium based microextraction techniques and the need for integrating and unite processes for better promotion and implementation of the principles of Green Analytical Chemistry. The resulted magnet integrated fabric phase sorptive extraction (MI-FPSE) device was the spearhead to develop a new analytical methodology for the determination of selected very common endocrine disrupting chemicals as model analytes in human urine by high-performance liquid chromatography-photodiode array analysis. More specifically, the sol-gel Carbowax 20 M coated on hydrophilic cellulose fabric substrate, MI-FPSE device was efficiently employed for the establishment of a new extraction protocol before the chromatographic determination. The sample preparation workflow was methodically optimized in terms of the elution solvent mixture, the volume of the sample, the extraction and the elution time, the stirring speed during the extraction, the ionic strength, and the pH of the sample matrix. The chromatographic separation was performed on a Spherisorb C18 column and a gradient elution program within 14 minutes. Mobile phase consisted of 0.05 ammonium acetate aqueous solution and acetonitrile. The method was validated towards linearity, sensitivity, selectivity, precision, accuracy, and stability. LOD and LOQ ranged between 1.05-1.80 and 3.5-6.0 ng/mL, while %RSD values were found lower than 9.0% in all cases. The method was efficiently applied to the bioanalysis of real samples. All the chosen EDCs were measured at high detection levels. The new MI-FPSE device has demonstrated its performance superiority as a magnet integrated stand-alone extraction device and could be considered as a significant improvement in the field of analytical/bioanalytical sample preparation.

Designing a moderately hydrophobic sol-gel monolithic Carbowax 20 M sorbent for the capsule phase microextraction of triazine herbicides from water samples prior to HPLC analysis.

The determination of triazine herbicides in water samples is of utmost importance, due to their persistence and excessive use. However, since the concentration of triazine pesticides in real samples is low, an extraction/preconcentration step is typically required. Capsule phase microextraction (CPME) is a recently introduced sample preparation technique in which highly efficient sol-gel sorbents are encapsulated in a tubular polymer membrane. This particular design integrates the filtration and stirring mechanism into one extraction device, enabling the application of CPME for in situ sampling. In this study, CPME coupled to high performance liquid chromatography-diode array detection (HPLC-DAD) was employed for the first time for the determination of six triazine herbicides (i.e., simazine, cyanazine, atrazine, prometryn, terbuthylazine and propazine) in water samples. Microextraction capsules containing a moderately hydrophobic sol-gel Carbowax 20 M sorbent provided the highest extraction efficiency towards the examined pesticides. The main parameters affecting the adsorption and desorption steps of the CPME procedure were investigated and optimized. Under the selected conditions, limits of detection (signal/noise = 3.3) were 0.15 ng mL-1 for the target analytes. Moreover, the relative standard deviation for the within-day and between-days repeatability were less than 7.2% and 9.9%, respectively. The method was successfully applied to the analysis of mineral water, tap water, rainwater and lake water samples. The reported protocol could overcome the need for sample filtration prior to the sample preparation of the water samples, resulting in simplification of the overall sample handling, improved data quality with minimal loss of analytes and reduced sample preparation cost.

An improved fabric-phase sorptive extraction protocol for the determination of seven parabens in human urine by HPLC-DAD.

An improved fabric-phase sorptive extraction (FPSE) protocol has been developed and validated herein for the simple, fast, sensitive and green determination of seven parabens-methyl paraben, ethyl paraben, propyl paraben, butyl paraben, isopropyl paraben, isobutyl paraben and benzyl paraben-in human urine samples by HPLC-DAD. The mobile phase consisted of ammonium acetate (0.05 m) and acetonitrile, while total analysis time was 13.2 min. Sol-gel poly (tetrahydrofuran) coated FPSE membrane resulted in optimum extraction sensitivity for the seven parabens. The novel FPSE medium as well as the improved and faster sample preparation procedure resulted in lower limit of detection and quantitation values in comparison with previously reported methods. The separation was carried out using an RP-HPLC method with a Spherisorb C18 column and a flow rate of 1.4 ml/min. The validation of the analytical method was carried out by means of linearity, precision, accuracy, selectivity, sensitivity and robustness. For all seven parabens, the limits of detection and quantitation were 0.003 and 0.01 µg/ml, respectively. Relative recovery rates were between 86.3 and 104%, while RSD values were <12.6 and 19.3% for within- and between-day repeatability, respectively. The method was subsequently applied to real human urine samples.

Fabric phase sorptive extraction combined with high-performance-liquid chromatography-photodiode array analysis for the determination of seven parabens in human breast tissues: Application to cancerous and non-cancerous samples.

An improved pretreatment approach of human breast tissue is demonstrated for subsequent analysis of seven parabens including methyl paraben (MPB), ethyl paraben (EPB), propyl paraben (PPB), butyl paraben (BPB), isopropyl paraben (iPPB), isobutyl paraben (iBPB), and benzyl paraben (BzPB). Specifically, a well-designed homogenization procedure, conjugated with an optimized fabric phase sorptive extraction (FPSE) protocol, resulted in a carefully outlined sample preparation process as part of a green, simple, sensitive, economical and fast HPLC-PDA analytical method in agreement with Green Analytical Chemistry (GAC) demands. Among all tested FPSE membranes, the highest extraction efficiency was achieved by employing sol-gel poly(tetrahydrofuran) (sol-gel PTHF) coating on 100% cotton cellulose fabric that represents a medium polarity microextraction device, which combined the advanced material characteristics of sol-gel sorbent and the rich surface chemistry of an inherent porous cellulose fabric substrate. The chromatographic separation was accomplished with a Spherisorb C18 column and an isocratic mobile phase consisted of ammonium acetate and acetonitrile at a flow rate of 1.4 mL/min. The total analysis time was 13.6 min. The analytical adequacy of the composite sample preparation and chromatographic separation method was strongly evidenced by its successful application in the bioanalysis of real cancerous and non-cancerous tissue samples originated from different sub regions of human breast including axila, the upper left and the right quadrant. In all samples, at least one paraben was detected, while 35% of the samples were tested positive for all seven target parabens. Moreover, concentration levels of parabens in cancerous tissues were unambiguously higher than in healthy tissues. The obtained results underlined bioaccumulation potential of parabens in human breast tissue as a consequence of constant low-dose exposure of humans, despite the statutory concentration limits. The developed methodology has demonstrated to be suitable and efficient for future epidemiological and toxicological studies.