Ultrasound-assisted cloud point microextraction of certain preservatives in real samples and determination by HPLC.

Ultrasound-assisted cloud point microextraction (UA-CPME) was performed for certain preservatives (p-hydroxy benzoic acid and its alkyl esters, methyl, ethyl, propyl and butyl parabens). Then, an HPLC method was developed for their simultaneous determination in pharmaceutical and cosmetic samples. The chromatograms of these substances were recorded on a C18 column using a gradient elution technique with various solvent systems at different flow rates and at 254 nm wavelength using a diode-array detector (DAD). The analysis conditions found by the classical method were optimized using the Box-Behnken design (BBD). In the design, the effect of each factor was examined with 3 and 4 factors for UA-CPME and HPLC analyses, respectively. The brij 58 concentration (BC), Na2SO4 amount (SA) and extraction time (ET) for UA-CPME, and the mobile phase 1 (MP1) ratio, mobile phase 2 (MP2) ratio, flow rate (FR) and column temperature parameters for HPLC analysis were obtained for the investigated levels. The factors affecting the resolution were determined by applying regression analysis to the experimental results. The analysis of variance (ANOVA) test was applied to ensure result reliability. The ANOVA test was used to determine the reliability of the results. A model was created with the obtained data. The developed method was validated by examining linearity, reproducibility, accuracy, limit of quantification and limit of the detection. Methyl paraben (with 0.148% RSD value and 0.060% relative error), and propyl paraben (with 0.149% RSD value and 0.120% relative error) were determined in the syrup sample by the developed method. Methyl paraben with recovery values of (98.32-99.42)% and ethyl paraben with recovery values of (99.17-99.41)%, were determined in a hand cream.

Determination of optimization parameters based on the Box-Behnken design for cloud point extraction of quinoline yellow using Brij 58 and application of this method to real samples.

Quinoline yellow (E104) dye is a food additive and generally used in cosmetics and drugs. In this work, polyethylene glycol hexa decyl ether (Brij 58) was used for the spectrophotometric determination of quinoline yellow (QY) in food and drug samples after cloud point extraction (CPE). Some parameters such as extraction temperature and time, pH, centrifuge speed, Brij 58 (surfactant) concentration, and Na2SO4 concentration were optimized using Box-Behnken design. The limit of detection (LOD) of this method was 0.0019 µg mL-1 for QY while the relative standard deviation (RSD) at low concentration levels (0.03 µg mL-1) was 1.32% (n = 5). Findings indicated that, this novel CPE method can be used quickly for the reproducible, selective and sensitive determination of QY dye in ordinary analysis.

Biosorptive detoxification of zearalenone biotoxin by surface-modified renewable biomass: process dynamics and application.

BACKGROUND: Contamination of food, feed, beverages and even drinking water with biotoxins is a growing global concern because of their potential health risks. In this work, surface-modified sugar beet pulp waste was used for the biosorptive removal of zearalenone biotoxin from contaminated aquatic media. RESULTS: Infrared, Boehm titration, BET (Brunauer-Emmett-Teller) surface area and point of zero charge analysis were employed for surface characterization. Kinetic and equilibrium studies showed that biotoxin biosorption was well predicted by the pseudo-second-order kinetic model and the Langmuir isotherm model. Zearalenone was removed from the solution over a wide pH range (3.0-8.0) and within a short time (15 min). Maximum uptake capacity of modified biomass was recorded as 23.30 ± 0.17 g kg-1 . Highest removal yield in a dynamic flow mode (94.56 ± 0.13%) was achieved at 2 mL min-1 flow rate using 30 mg biosorbent. Regeneration experiments revealed high reusability potential of suggested biosorbent. Moreover, its application potential was tested in spiked samples of malt, beer and canned corn liquid. CONCLUSION: Detoxification potential of this renewable biomass was significantly enhanced after modification. Modified biomass could be used as an efficient and low-cost green-type material with good application potential for zearalenone detoxification. © 2018 Society of Chemical Industry.

A validated capillary electrophoretic method for the determination of indacaterol and its application to a pharmaceutical preparation.

Indacaterol is a new inhaled ultra-long acting ß2-agonist. It has been recently approved in the European Union for the treatment of chronic obstructive pulmonary disease. This paper reports, for the first time, a method for the determination and validation of Indacaterol (IND) using an internal standard in capsules. Capillary electrophoretic separation was performed on an uncoated fused-silica capillary (50 cm effective length, 75 µm i.d.) and background electrolyte composed of 20 mmol L-1 of sodium tetraborate buffer, 15% (v/v) methanol (pH = 10.0) with the application of 20 kV of potential; 10 s at 5 × 103 N m-2 (50 mbar) of injection time; and wavelength of 200 nm and 25 °C of temperature. The linearity was evaluated in the range of 4.90 × 10-6 mol L-1 (2.50 µg mL-1) and 3.94 × 10-5 mol L-1 (20.00 µg mL-1), with R = 0.9993 for inter-day. LOD and LOQ values were 2.18 × 10-8 mol L-1 (0.011 µg mL-1) and 7.25 × 10-8 mol L-1 (0.037 µg mL-1) for inter-day, respectively. The precision values were 0.50-1.06% for intra-day and 2.12% for inter-day as RSD%. The accuracy was tested by the standard addition method with the recovery values being between 98.79 and 99.09 as percentages with RSD% interval of 0.01-0.80. The developed method was validated according to ICH guidelines. Indacaterol was successfully determined in Arcapta® capsule dosage form by the validated CE method with a relative error of 0.28%. The result was within the requirements of the USP 34-NF29. Therefore, the validated method may be used for the determination of Indacaterol in its capsules in quality control laboratories.

A Validated Capillary Electrophoretic Method for the Determination of Olopatadine and Its Application to a Pharmaceutical Preparation of Eye Drops.

A validated rapid and sensitive capillary zone electrophoretic method for the determination of olopatadine hydrochloride (OLO) is described. Optimum conditions were found: 20 mmol/L sodium tetraborate buffer, acetonitrile 15% (v/v), 10 mmol/L NaCl at pH 9.5, with 25 kV of applied potential, injection time of 10 s at 5 × 103 N/m2, at a wavelength of 205 nm, and fixed temperature of 30°C. The calibration curve was linear in the range of 1.13 × 10-5 mol/L (4.22 µg/mL) to 5.65 × 10-5 mol/L (21.12 µg/mL), with R = 0.9995 for interday precision. LOD and LOQ values were 1.58 × 10-6 (0.58 µg/mL) and 4.78 × 10-6 mol/L (1.75 µg/mL), respectively. Precision values were 1.10-1.97% for intraday and 1.41% for interday RSDs. Accuracy was tested by preparing a synthetic mixture whose composition was similar to the pharmaceutical preparation for Patanol. The RSDs of the recovery values (98.2%) were between 0.42 and 0.65% and the amount of OLO found was 1.09 mg/mL. The result was within the requirements of USP 31-NF 26. Therefore, this validated method is suggested for routine analysis for the determination of OLO in laboratories.

A rapid determination of patulin using capillary zone electrophoresis and its application to analysis of apple juices.

This study describes a capillary zone electrophoretic method for the determination of patulin. An optimum run buffer was found to be 25 mM of sodium tetraborate and 10% acetonitrile (v/v) at pH 10. Optimum conditions were determined to be: an applied voltage of 25 kV (normal polarity), temperature of 25°C and injection time of 10 s at 50 mbar; the signals of patulin and phenobarbital as internal standard were detected at 276 nm. The method was highly reproducible, with relative standard deviations of 0.02-0.85 for intra-day and 0.04-0.42 for inter-day for standard patulin. Acceptable linearity [y = 0.0020C (µg/L) - 0.0680 (r = 0.9999)] was obtained over a concentration range of 0.25 to 4.99 µg/mL of patulin. The limits of detection and quantification were calculated to be 5.9 × 10(-3) and 1.79 × 10(-2) µg/mL, respectively. Recovery was 68.0%. The proposed method was applied to 21 apple juice samples purchased from different Turkish markets, and two were found to contain higher than the limits of the European Union Directive for patulin.