Pesticide analysis - group proof

Dithio carbamates

Dithio carbamates are detected and quantified as CS2 separators (and also to DFG S19). The measurement is done by means of GC-MS/MS on a Saturn 2000 (ion trap). The proof threshold is below 0.05 mg CS2/kg. The samples are prepared by acid hydrolysis, the separated carbon bisulphide is extracted by means of SPME (solid-phase micro-extraction) and injected into the GC-MS system (automatic system).

Protective leaf fungicides

Organotin compounds

Tri-butyl tin compounds such as tri-butyl tin oxide are used as biocides, inter alia in shipping (anti-fouling). Mono and dibutyl tin compounds can be found in plastics as so-called stabilisers. Tri-phenyl tin (trade name Fentin: fungicide, algicide, molluscicide) is used in the cultivation of potatoes, celery, beet, onions. peanuts, beans, grain and rice. The organotin compounds demand their own sample preparation with a subsequent derivatisation for the determination by means of GC-MS.

Phenyl ureas

These herbicide agents are only determined in water samples and soil samples. The extracts obtained from the solid phase or liquid extraction are derivatised and subsequently examined by means of GC-NPD/ECD or GC-MS. In these determinations, unambiguous derivatives which can clearly be attributed to the original active agents are obtained.

Phenoxy-carbon acid

The detection of phenoxy-carbonic acids in water is according to DIN method 38407 part 20 (solid phase extraction, derivatisation with Diazomethan with a subsequent GC-MS measurement).

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