Simultaneous determination of glucose, fructose, sucrose and sorbitol in the leaf and fruit peel of different apple cultivars by the HPLC-RI optimized method.

A high performance liquid chromatography method with refractive index detection (HPLC-RI), for simultaneous determination of glucose, fructose, sucrose and sorbitol in leaf and/or apple peel samples from nine apple (Malus domestica Borkh.) cultivars and rootstocks, originating from a germplasm collection, has been developed and validated. Box-Behnken design of response surface methodology was applied for the method optimization. The Carbosep Coregel 87H3 column was used under the optimum conditions predicted: mobile phase of H2SO4 0.005 mol L(-1) solution, flow rate of 0.3 mL min(-1) and column temperature of 35°C. The method was validated for linearity (R(2)>0.99), limits of detection (2.67-4.83 µg mL(-1)) and quantification (8.9-16.1 µg mL(-1)), precision (%RSD<5.05) and recovery (93.94-103.06%) and satisfactory results obtained. The sugars content varied across micropropagated plants in vitro, plants regenerated after cryostorage, growing trees in vivo, and fruit peel.

Determination of four acidic nonsteroidal anti-inflammatory drugs in wastewater samples by dispersive liquid-liquid microextraction based on solidification of floating organic droplet and high-performance liquid chromatography.

A simple, environmentally friendly, and sensitive dispersive liquid-liquid microextraction based on solidification of floating organic droplet for the extraction of four acidic nonsteroidal anti-inflammatory drugs (ketoprofen, naproxen, ibuprofen, and diclofenac) from wastewater samples subsequent by high-performance liquid chromatography analysis was developed. The influence of extraction parameters such as pH, the effect of solution ionic strength, type of extraction solvent, disperser solvent, and extraction solvent volume were studied. High enrichment factors (283-302) were obtained through the developed method. The method provides good linearity (r > 0.999) in a concentration range of 1-100 µg/L, good intra- and inter-day precision (relative standard deviation < 7%) and low limits of quantification. The relative recoveries of the selected compounds were situated over 80% both in synthetic and real water samples. The developed method has been successfully applied for the analysis of the selected compounds in wastewater samples.

Simultaneous determination of nitrophenols and poly-aromatic hydrocarbons in aquatic samples by solid phase extraction and HPLC analysis.

A method for the simultaneous extraction and HPLC analysis of nitrophenols and poly-aromatic hydrocarbons (PAHs) in aquatic samples is presented. The efficiency of the solvent extraction and the solid phase extraction (SPE) is compared. The results showed that the polymeric SPE sorbent is the best compromise for the simultaneous extraction of the tested compounds taking into consideration the lipophilicity of PAHs and the polarity of nitrophenols. The best results were obtained on polymeric Strata X sorbent, elution with dichloromethane followed by elution with methanol. Silica gel C18 sorbent is improper for nitrophenols due to the strong interactions with the residual hydroxyl groups of silica gel. The developed SPE-HPLC method was successfully applied for the analysis of these pollutants in different water samples.