Automated continuous-flow in-syringe dispersive liquid-liquid microextraction of mono-nitrophenols from large sample volumes using a novel approach to multivariate spectral analysis.

Continuous magnetic stirring-assisted dispersive liquid-liquid extraction followed by dispersive backextraction as a novel pre-treatment technique for adaptable and milliliter volumes of environmental samples has been developed. The procedure was automated using the technique "Lab-In-Syringe". The void of the automated syringe pump was used as size-adaptable extraction chamber. By a flow channel in the syringe piston, continuous flow through the syringe void was enabled. 1-Octanol was used as an extractant and dispersed by the action of a magnetic stirring bar, which was placed inside the syringe and driven by an external rotating magnetic field. Extract washing and dispersive backextraction in an alkaline aqueous acceptor phase were carried out after the preceding extraction from the acidified water sample. Analyte determination was achieved using multivariate spectrum analysis. The method was applied to determine priority pollutants, mono-nitrophenols, in surface water and enabled to reach limits of detection for o-, m-, p-nitrophenol (λ = 418, 390, 400 nm, respectively) of 0.14, 0.26, and 0.02 µmol L-1 (19.5, 36.2, and 2.8 µg L-1), respectively. Under optimized conditions, relative standard deviations were generally less than 5% and enrichment factors of o-, m-, p-nitrophenol 19, 25, and 21, respectively, were achieved using sample volumes of up to 24 mL. Average recoveries of o-, m-, p-nitrophenol from spiked surface water were 94, 82, and 92%, respectively. The concentration of humic acid was found 6-times reduced with respect to the analyte. In addition, adding spectral background modeling allowed nitrophenol determination with precision adequate for routine analysis.

Psychometric evaluation of the German Version of the Supportive Care Needs Survey for Partners and Caregivers (SCNS-P&C-G) of cancer patients.

This study aimed for psychometric validation of the German version of the Supportive Care Needs Survey for Partners and Caregivers (SCNS-P&C-G). In- and outpatients with lung, urological and gastrointestinal cancer at Heidelberg University Hospital in Germany and in each case one relevant caregiver were asked to complete a set of questionnaires assessing their unmet needs together with distress, depression, anxiety and caregiver strain. In addition, medical data of the patients were collected. Fully completed questionnaires were received from 188 pairs of patients and their caregivers. Using exploratory factor analysis, four domains of unmet needs were identified with an appropriate variance explanation (58.7%) and acceptable (>0.70) internal consistencies (α = 0.95 to 0.76) for each domain. Convergent validity was found with respect to significant positive correlations (>0.40) of the SCNS-P&C-G domains with caregivers' anxiety, depression and strain. Although poorer health status of the patient indicated more unmet caregiver needs, this finding was not consistent for all need domains. Overall, associations were only moderate to weak pointing out the necessity of a separate screening for caregivers' needs. The findings of this study support that the SCNS-P&C-G is an appropriate research instrument to assess caregivers' needs on different domains throughout the disease trajectory.

Automation of simultaneous release tests of two substances by sequential injection chromatography coupled with Franz cell.

This presented paper deals with a methodology for the separation and simultaneous determination of two active substances in topical pharmaceutical formulation composed of lidocaine (L) and prilocaine (P). The methodology described is based on the sequential injection chromatography (SIC) with UV detection. Monolithic Column Chromolith Flash RP-18, 25mmx4.6mm (Merck, Germany) was used. Separation was performed using elution with binary mobile phase composed of acetonitrile-phosphate buffer 0.05M (40:80 (v/v))+0.01% triethylamine (adjusted to pH 7.1 with H(3)PO(4)) at a flow rate of 0.6mlmin(-1). The analysis duration was <7min. The method was linear over the range of 2.5-200mgl(-1) with a detection limit of 0.25mgl(-1) for both substances. The system was then coupled with Franz cell. Fully automated system for the in vitro release testing of semisolid dosage forms based on sequential injection analysis (SIA) was developed. Simultaneous measurement of L and P release was done by this system. Samples were taken in 10.5min intervals during 4h of the release test. Each test was followed by calibration with five standard solutions. Receiving medium was replenished automatically by the system.

Automated system for release studies of salicylic acid based on a SIA method.

The aim of this work was to describe a fully automated system for the in vitro release testing of semisolid dosage forms based on SIA technique. The system was tested for monitoring release profiles of different ointments containing 3% of salicylic acid (Belosalic, Diprosalic, Triamcinolone S). The native fluorescence of salicylic acid was used for fluorimetric detection. Phosphate buffer pH 7.4 was the receptor medium; samples were taken at 10 min intervals during 6 h of the release test; and each test was followed by calibration with five standard solutions. The linear calibration range was 0.05-10 microg ml(-1) (r = 0.9996, six standards); the maximal SIA sample throughput for this system was 120 h(-1), sample volume being 50 microl and flow rate 50 microl s(-1). The detection limit for salicylic acid was 0.01 microg ml(-1).

[Effect of manganese (II), cobalt (II), and nickel (II) ions on the growth and production of coumarins in the suspension culture of Angelica archangelica L]. / Vliv manganatých, kobaltnatých a nikelnatých iontu na rust a produkci kumarinu v suspenzní kulture Angelica archangelica L.

The plant cell reacts to an increased concentration of metals in the environment by various mechanisms. They include an increase in the formation of heat-shock proteins, metallothioneins, phytochelatins, amino acids (cysteine, histidine), organic acids (citric, malic), or secondary metabolites. The latter mechanism is being investigated for its possible use in explant cultures for the stimulation of secondary metabolism, which is the source of substances of pharmaceutical importance. The study tested manganese (II) (0, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, and 50 mM in the medium), cobalt (II), and nickel (II) ions (0, 0.1, 0.5, 1, 5, 10, 50, 100, 200, and 500 microM in the medium) as potential elicitors of coumarin production. At the same time, toxicity of these metals for the culture was examined by evaluating their effect on growth (characterized by fresh and dry weight of biomass at the end of a two-week cultivation). Cultures were cultivated in the dark and in the light. It has been found that the growth of cultures is not influenced by manganese in concentrations ranging from 0 to 2 mM, then it slightly decreases, at a concentration of 50 mM it is lower by 20 % when cultivated in the dark and by 30 % when cultivated in the light in comparison with the control. Cobalt in concentrations of 0 to 50 microM does not significantly influence the growth of the culture, higher concentrations decrease the biomass yields, more markedly when cultivated in the light (at 500 microM Co by 60 %, in the dark only by 30 % in comparison with the controls). Nickel in concentrations of 0.1 to 200 microM does not influence growth, and in a concentration of 500 microM decreases it by approximately 30 % in comparison with the control both in the light and dark. Production of coumarins was not stimulated by any metal in comparison with the control cultures, only the removal of manganese from the medium in the culture cultivated in the dark increased production by about 15 % versus the control.

Determination of rhodamine 123 by sequential injection technique for pharmacokinetic studies in the rat placenta.

The sequential injection (SIA) technique was applied in pharmacokinetic studies of the transporter-mediated passage of a model substrate, rhodamine 123 (Rho123), through the dually perfused rat term placenta. The method described was used for real-time monitoring of Rho123 concentrations in both the maternal and fetal compartments. Determination was processed by fluorescence detection (lambda(ex)=480 nm, lambda(em)580 nm); calibration curve was linear over the range 0.01-50 mumoll(-1) (r=0.99965), detection limit was 10 nmoll(-1) (3sigma) and RSD2% (10 readings). Transport of Rho123 was scanned under various conditions (ATP-synthesis inhibition) and several inhibitors of P-glycoprotein transporter were tested (e.g. quinidine). The advantages of the modern SIA method-an automated analytical tool providing both fast and precise analysis-were successfully demonstrated for examination of transport profiles to investigate the effect of P-glycoprotein on the placental transfer of Rho123.

Automated sequential injection fluorimetric determination and dissolution studies of Ergotamine Tartrate in pharmaceuticals.

A fully automated flow system for drug-dissolution studies based on the sequential injection analysis (SIA) was described and used for monitoring dissolution profiles of Ergotamine Tartrate (ET) in pharmaceutical formulations. 50 mul of dissolution medium was taken for each measurement at a flow rate of 40 mul s(-1) and detected by fluorescence detector using lambda(ex)=236 nm (lambda(em)>/=390 nm). The calibration curve was linear over the range 0.03-0.61 mg l(-1) of ET (sufficient for the dissolution tests). Equation of the calibration curve was calculated giving the following values: F=117.7 c+0.80 (n=6); r=0.9998. Detection limit was 0.01 mg l(-1) of ET. The R.S.D. is less than 0.54 and 0.86% (n=10) when determining 0.61 and 0.03 mg l(-1) of ET in standard solution, respectively. The dissolution test of Bellaspon tablets (0.3 mg of ET in 1 tablet) was programmed for 20 min, with a continuous sampling rate of 120 h(-1) under conditions required by BP 1993.