[Treatment of chronic pain with drug addicts].

Background: The therapy of chronic pain of primarily drug addicted patients is a problem which has hitherto remained unresolved within the field of pain therapy. Synergistic effects of the prescribed medicine with additionally taken drugs or medicine which can lead to an unpredictable increase of effect of prescribed opioids are of special significance. When addiction and pain appear simultaneously medical aspects of the syndrome of addiction have to be implemented within the framework of coordinated therapy.

European standardization of methods for pesticide residue analysis in foods--current status.

The aim of this paper is to inform all scientists working in pesticide residue analysis on the contents, size and background of European standards (ENs) in this area. These ENs were established by a Technical Committee (TC 275, of the European Committee for Standardization (CEN, and each CEN member country is obliged to implement them as national standards. EN 1528:1996 comprises eight methods for the multiresidue determination of organochlorine pesticides and polychlorinated biphenyls (PCBs) in fatty foods.

A new parameter for checking the suitability of alpha-tocopherol standards.

The quality of an alpha-tocopherol standard can be checked easily by measuring the UV absorbance at minimum (255 nm, Amin) and maximum (292 nm, Amax) wavelengths in n-hexane. If the quotient Amin/Amax exceeds 0.18, the standard contains less than 90% alpha-tocopherol and the determination at 292 nm will yield inaccurate results.

Solid phase extraction for the confirmation of results in polar pesticides residue analysis by HPTLC.

HPTLC is a convenient method for confirming the presence and identification of pesticide residues following gas chromatographic analysis of sample solutions obtained by clean-up according to the Deutsche Forschungsgemeinschaft multiresidue method S 19. For several crops, however, the polar eluates 4 and 5 obtained from the small silica gel column are abounding with co-extractives which interfere with HPTLC determination and also with GLC in some cases. They are effectively removed by solid phase extraction on a small aminopropyl cartridge, using a tertbutyl methyl ether/methanol (99 + 1) mixture as the eluant.

Polychlorinated biphenyl residues in food and human milk: determination of co-planar and mono-ortho substituted congeners.

An analytical method is described for determining the residues of coplanar as well as mono-ortho substituted PCB congeners both exhibiting toxicological relevance, in foods of animal origin and in human milk. The unsophisticated procedure, convenient for routine analyses, includes the extraction of lipids, clean-up steps using liquid/liquid partition and column chromatography, fractionation of the congeners using HPLC on a special carbon column with an optimal gradient elution, and capillary column gas chromatography with electron capture or mass spectrometric detection. As preliminary results indicate, the low-chlorinated PCB technical products contribute more to the actual contamination of environment and foods than has been estimated so far.