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The objective of this thesis is the quantification and qualification of neonicotinoid insecticides using thin-layer chromatography (TLC). Neonicotinoids are a relatively new form of pesticides, which have been proven to be extremely lethal to the honey bee, Apis mellifera. In this paper six forms of neonicotinoid insecticides (i.e. Acetamiprid, Thiacloprid, Imidacloprid, Clothianidin, Thaimethoxam, and Nitenpyram) are analysed. The initial steps are to first find a suitable mobile phase eluent, followed by the search for a reagent causing a luminescence effect of the neonicotinoids on a TLC plate. Subsequently, a calibration method is then used to find the detection limit of this TLC experiment. The aim is, therefore, to achieve a standard method of quantifying and qualifying neonicotinoids via TLC. Whilst a suitable mobile phase has been established, an optimal fluorescent reagent has yet to be found and more research on the subject must be carried out.
We present a video-densitometric quantification method for the pain killer known as diclofenac and ibuprofen. These non-steroidal anti-inflammatory drugs were separated on cyanopropyl bonded plates using CH2Cl2, methanol, cyclohexane (95 + 5 + 40, v/v) as mobile phase. The quantification is based on a bio-effective-linked analysis using Vibrio fisheri bacteria. Within 10 min a CCD-camera registered the white light of the light-emitting bacteria. Diclofenac and ibuprofen effectively suppressed the bacterial light emission which can be used for quantification within a linear range of 10 to 2000 ng. The detection limit for ibuprofen is 20 ng and the limit of quantification 26 ng per zone. Measurements were carried out using a 16-bit ST-1603ME CCD camera with 1.56 megapixels (from Santa Barbara Instrument Group, Inc., Santa Barbara, USA). The range of linearity covers more than two magnitudes because the extended Kubelka-Munk expression is used for data transformation. The separation method is inexpensive, fast, and reliable.