No abstract

This paper describes a selective and sensitive method that uses liquid chromatography/tandem mass spectrometry with positive electrospray ionization (ESI+) for the determination of deltamethrin in a variety of crops. Samples were extracted by conventional high-speed blending. Some samples required no further cleanup; others were cleaned up by gel permeation chromatography, strong cation-exchange cartridges, or partitioning with n-hexane. In the determinative step, the buffered neutral mobile phase, consisting of 10 mM ammonium acetate (pH 6.8) and methanol, and ESI+ provided strong ammonium adduct formation to [M+NH4]+ at m/z 523, and the multiple-reaction monitoring (MRM) transition at m/z 523/281 was used for the quantitation of deltamethrin. A second MRM transition at m/z 525/283 was used for confirmation. The limit of quantitation (LOQ) values were 0.01 mg/kg for edible materials and 0.05 mg/kg for nonedible materials. Mean overall recoveries at the LOQ and the 10-fold LOQ ranged from 73 to 96%, and the relative standard deviations were <10% for all samples materials analyzed.

The secondary product patterns of eleven Lasallia-species, L. asiae-orientalis Asah., L. brigantium (Zsch.) Llano, L. capensis (Frey) Llano, L. hispanica (Frey) Sancho & Crespo, L. membranacea (Laur.) Llano, L. papulosa (Ach.) Llano , L. pensylvanica (Hoffm.) Llano, L. pertusa (Rass.) L lano, L. pustulata (L.) Merat, L. rossica Dombr. und L. sinensis Vej are investigated by hplc. In addition to gyrophoric acid, lecanoric acid, umbilicaric acid, 7-chloroemodin, valsarin and skyrin, which were described before, hiascic acid and ovoic acid were found by means of hplc-cochromatography , UV -and mass spectrometry and the reac­tion of hiascic acid with acetone. The secondary product pattern of Lasallia-species is useful for systematic purposes. A key of the species is provided. The distribution of secondary prod­ucts within the thalli is discussed.

The secondary product pattern of 38 specimens of Lasallia brigantium (Zsch.) Llano, L. hispanica (Frey) Sancho & Crespo and L. pustulata (L.) Merat were investigated by HPLC. A c­ cording to previous publications gyrophoric acid, lecanoric acid and umbilicaric acid were detected. Additionally two further unknown depsides were found. The presence of the anthraquinone skyrin, new to Lasallia, was shown for L. hispanica and L. pustulata. Skyrin is not equally distributed within the thalli but mainly concentrated in the umbilicus. In L. hispanica skyrin is located in the epihymenium, too. A correlation between secondary product pattern and thallus size or light supply does not exist.