The sensing properties of a conducting polymer, polypyrrole (PP), are modified by competitive doping with tetrafluoroborate or perchlorate and tetrasulfonated metallophthalocyanines (MPcTS, M=Ni or Cu). The Kelvin probe responses of these polymers to dimethylmethylphosphonate, tetrachloroethene and NO _x are compared with Kelvin probe signals of commonly prepared polypyrrole, doped with only one anion such as tetrafluoroborate, perchlorate, toluene-p-sulfonate, NiPcTS and CuPcTS. Improved sensing properties were achieved due to competitive doping with the above mentioned anions, compared to commonly prepared PP. The detection range for NO _x is 0.4–40 ppm in ambient air and 2–40 ppm in ambient air for dimethylmethylphosphonate. The sensitivity to both substances lies in the range of 67–83 mV (ppm decade) ^-1 .

A simple, cost-effective headspace gas chromatography (GC) method coupled with GC with flame ionization detection for simultaneous determination of methanol, ethanol and formic acid was developed and validated for clinical and toxicological purposes. Formic acid was derivatized with an excess of isopropanol under acidic conditions to its volatile isopropyl ester while methanol and ethanol remained unchanged. The entire sample preparation procedure is complete within 6 min. The design of the experiment (the face-centered central composite design) was used for finding the optimal conditions for derivatization, headspace sampling and chromatographic separation. The calibration dependences of the method were quadratic in the range from 50 to 5,000 mg/L, with adequate accuracy (89.0–114.4%) and precision (<12%) in the serum. The new method was successfully used for determination of selected analytes in serum samples of intoxicated patients from among those affected by massive methanol poisonings in the Czech Republic in 2012.