Quantification of some active compounds in air samples at pharmaceutical workplaces by HPLC.

Workers involved in the manufacture of drug substances may be exposed to active pharmaceuticals by inhalation of drug dusts or droplets which has been considered the main exposure route. The proposed HPLC method allowed to determine sulpiryde, hydroxyurea and dyprophylline in the concentration range of 0.01-0.187 mg/m3, 0.001-0.08 mg/m3 and 0.01-0.40 mg/m3 for sulpiryde, hydroxyurea and dyprophylline, respectively, when 480 L of air sample was collected on the glass fibre filters. Sulpiryde was extracted with a solvent system consisting of acetonitrile-phosphate buffer at pH 3 (85:15, v/v), while the best efficiency of extraction for hydroxyurea and dyprophylline was achieved using water. HPLC analysis of sulpiryde with fluorescence detection was more sensitive (LOD=3.1 microg/L) in comparison with UV detection (LOD=84.4 microg/L).

Screening and optimization of derivatization in heating block for the determination of aliphatic aldehydes by HPLC.

For the study of the derivatization behavior of aliphatic C1-C10 aldehydes with 2,4-dinitrophenylhydrazine (DNPH) in a heating block a gradient elution HPLC method for separation and determination by UV detection at 360 nm was applied. The influence of time, temperature, excess of reagent and stirring onto the reaction yields were examined for conducting the reaction in a thermostated heating block. First, the derivatization procedure had been screened by experiments according to a complete factorial design in order to evaluate the statistically significant variables. Those parameters were used to establish the optimum conditions for the reaction by means of a Box-Behnken design.

Chromatographic separation of chlorophenoxy acid herbicides and their radiolytic degradation products in water samples.

HPLC procedure for simultaneous determination of chlorophenoxy acid herbicides and their radiolytic degradation products in waters is described with the use of octadecylsilica column and spectrophotometric detection at 280 nm. The satisfactory separation was achieved with a mobile phase of pH 2.5 consisting of 43.7 mM acetic acid with 40% (v/v) acetonitrile. Limit of detection values for herbicides and phenol derivatives were in the range of 19-41 microg/l and 10-60 microg/l, respectively. The developed method was applied for monitoring the effectiveness of radiolytic degradation of herbicides. Studies of products of gamma-radiolysis of 2,4-dichlorophenol have shown that the efficiency of this process is affected by the presence of naturally occurring scavengers of gamma-radiation such as carbonates or nitrates.

Analysis of selenium species by capillary electrophoresis.

The presence of selenium in the form of different species in environmental and biological samples receives an increasing attention due to better understanding of its bioavailability, toxicity and transport mechanism. For many years, gas and liquid chromatography have been extensively explored in speciation analysis of this element. Recently, capillary electrophoresis (CE) has made much progress in this field. This review presents the developments in the application of CE for simultaneous separation and determination of different selenium compounds. Various separation approaches and detection methods as well as pre-concentration techniques are discussed. The speciation performance of CE is illustrated by a number of practically relevant applications.

Preconcentration of metal ions on porphyrin-modified sorbents as pretreatment step in AAS determination.

The preconcentration of some divalent metal ions by complexation with carboxyphenylporphyrin (TCPP) and retention on conventional anion-exchange resins and a non-ionic sorbent was examined. Two different procedures--ligand in solution or immobilised on the solid sorbents--were evaluated as a function of pH. The selectivity order for metal ions on the TCPP-loaded resin Amberlite IRA-904 was established as: Pb(II)>Ni(II)>Cu(II)>Cd(II)>Mg(II).

Monitoring of platinum in the environment.

Since the introduction of catalytic converters for the control of vehicle emission, a controversial discussion has begun on platinum emission and its eventual consequences for the environment. This brief overview covers the main aspects of anthropogenic emission of platinum and its bioavailability. Modern analytical methods for Pt determination in different environmental samples are also presented.

Porphyrins in analytical chemistry. A review.

The porphyrins, naturally occurring macrocyclic compounds, have, in the last 10 years, gained increasing interest in analytical chemistry. This review based on 123 original literature references, mostly published in the 1990s, presents catalytic applications of metalloporphyrins in electroanalysis as electroactive agents in ion selective membranes, as unique reagents in spectrophotometry and as new stationary phases offering unusual resolution in HPLC. The collected data are also presented in four tables.

Recent advances in solid-phase extraction of platinum and palladium.

Increasing platinum concentrations have been detected in environmental samples since the introduction of catalytic converters used in cars. Also the intensive use of platinum-based anti-tumor drugs led to interest in the determination of trace amounts of platinum absorbed by the human body and of the physiological effect of its complexes on living organism. However, detection of Pt and Pd in environmental and biological samples with complex matrices, has to be generally preceded by a preconcentration/separation step. A brief overview of the application of solid sorbents for these procedures based on published data is presented. Attention is also paid to preparation of the samples and detection methods usually used for determination of platinum and palladium.

The application of solid sorbents for the purification of aluminum contaminated chemicals used as modifiers in electrothermal atomic absorption spectrometry.

Various microcolumns with solid sorbents (ion exchange resins, functionalised cellulose sorbents, chelating resins) have been tested with respect to their ability for the purification of aluminum contaminated chemicals used as modifiers in electrothermal atomic absorption spectrometry. The purification of NaNO(3), Mg(NO(3))(2), K(2)SO(4) and (NH(4))(2)HPO(4) has been the most effective with an almost 100% efficiency, when Spheron-Oxine was used as chelating resin. The sorption of aluminum from KOH solution has been found to be very high (around 90%) for all investigated sorbents. However, the best results have been obtained with anion-exchange resins. It has been difficult to purify concentrated mineral acids (HCl, H(2)SO(4)). A retention of aluminum above 80% has been achieved only when Cellex P, Chelex 100 or Amberlite XAD-2 have been used.

Chemical speciation by flow-injection analysis. A review.

Speciation of elements in natural matrices, especially of trace metals, is one of the predominant development trends of modern inorganic analysis. The main part of the conventional speciation procedures is a suitable combination of separation and chemical conversion steps, for which the most appropriate methodology seems to be the use of flow-injection. A shorter time of performance of these operations in flow-injection manifolds is advantageous in terms of avoiding the shift of chemical equilibria during the speciation measurement. Numerous other advantages are also pointed out in this review based on 58 references. Among flow-injection analysis methods published so far for speciation the determination of different oxidation states predominates, while a much smaller number of papers have been published on the determination of the degree of complexation or the determination of organometallic compounds.

Flame AAS determination of lead in water with flow-injection preconcentration and speciation using functionalized cellulose sorbent.

The on-line solid phase extraction of trace amount of lead in flow-injection system with flame AAS detection was investigated using cellulose sorbents with phosphonic acid and carboxymethyl groups, C(18) sorbent non-modified and modified with Pyrocatechol Violet or 8-quinolinol, commercial chelating sorbents Chelex 100 and Spheron Oxin 1000, non-polar sorbent Amberlite XAD-2 modified with Pyrocatechol Violet and several cation-exchange resins. The best dynamic characteristics of retention were observed for functionalized cellulose sorbents. For Cellex P assumed as optimum sorbent, elution with a separate fractions of nitric acid and ethanol allows the differentiation between tetraalkyllead and sum of inorganic lead and organolead species of smaller number of alkyl groups. The detection limit for the determination of inorganic Pb(II) was estimated as 0.17 microg/l. at preconcentration from 50 ml sample at a flow rate of 7 ml/min.

Atomic absorption spectrophotometric determination of gold with preconcentration by Donnan dialysis.

Donnan dialysis enrichment with tubular cation-exchange membrane was used as a preconcentration method prior to determination of gold by flame atomic absorption spectrometry (FAAS). The value of enrichment factor can be controlled for a particular application through adjustment of the membrane tuning length, dialysis time, carrier flow rate, composition of the receiver solution and by addition of complexing ligand to the receiver or the sample solution. For 10 min dialysis enrichment factor above 3 can be achieved. The detection limit (signal-to-noise ratio = 3) of 35 ng/ml was obtained. RSD at 0.2 mug/ml level was 4.7% (n = 6). The results of dialysis of noble metals mixtures are demonstrated.