Publication: Katı faz mikroekstraksiyon yöntemi ile pestisitlerin gaz kromatografisinde tayini
Abstract
KATI FAZ MİKROEKSTRAKSİYON YÖNTEMİ İLE PESTİSİTLERİN GAZ KROMATOGRAFİSİNDE TAYİNİ Katı faz mikroekstraksiyon, organik faz kaplama üzerine maddelerin adsorpsiyonuna ve gaz kromatografi cihazına enjeksiyon ile desorpsiyonuna dayanan yeni bir analitik tekniktir. Sebze ve meyvelerdeki pestisid kalıntı düzeylerinin belirlenmesi, pestisidlerin canlı sağlığına ve çevreye olan zararlı etkileri nedeniyle oldukça önemlidir. Bu amaçla, çilek ve salatalık örneklerinde yaygın olarak kullanılan organoklorlu pestisid kalıntı düzeylerinin saptanmasına yönelik yeni bir katı faz mikroekstraksiyon yöntemi geliştirilmeye çalışılmaktadır. Geliştirilen metotta, örnekler metanol:su (%20:%80) karışımı ile muamele edildikten sonra PDMS/ DVB fiber kaplama ile ekstrakte edilmektedir. Elde edilen ekstraktlar, Gaz Kromatografisi/ Kütle Spektrometresi (GC/ MS)’ne enjekte edilerek, Split/ Splitless modunda analiz edilmektedir. GC/ MS HP-5MS kolon kullanılarak, geliştirilen programla, 18 pestisid içeren karışım analiz edildi. Metodun geçerli validasyonu yapılmış ve sonuçlar kabul edilir aralıklarda bulunmuştur. Pestisidlerin matrikste hazırlanan kalibrasyonlardan elde edilen korelasyon katsayıları (r2) 0.92-0.99 arasındadır, geri kazanımlar % 63-99 arasında, LOD değerleri 0.245-0.493 µg/ L ve relatif standart sapmaları (% RSD) %20’den düşük bulunmuştur.
DETERMINATION OF PESTICIDES IN GAS CHROMATOGRAPHY WITH SOLID PHASE MICROEXTRACTION METHOD Solid Phase Micro-Extraction (SPME) is a new analytical technique, based on capturing the analytes by adsorption onto an organic phase coating a glass fibre, and subsequent direct desorption into the injector of a gas chromatograph. Determination of pesticide levels is quite important due to their effect on health and environment in fruit and vegetables. In this research, a new method of solid-phase microextraction has been established for organochlorine pesticide residues in strawberry and cucumber. In developed method, samples were treated with methanol:water (20%:80%) mixture and extracted with PDMS/ DVB fiber coating. The extracts were than injected to Gas Chromatography/ Mass Spectrometry (GC/ MS) and analysed in Split/ Splitless. HP5-MS column was used in GC/ MS and 18 pesticide mix.were formed with developed run programme. Method was validated and validation parameters were in acceptable range. Pesticides, correlation coefficients were found between (R2) were 0.92-0.99 with matrix matched calibration, recoveries were found between 63-99%, LOD were found between 0.245-0.493 µg/ L and relative standart deviations (RSD%) were lower than 20%.
DETERMINATION OF PESTICIDES IN GAS CHROMATOGRAPHY WITH SOLID PHASE MICROEXTRACTION METHOD Solid Phase Micro-Extraction (SPME) is a new analytical technique, based on capturing the analytes by adsorption onto an organic phase coating a glass fibre, and subsequent direct desorption into the injector of a gas chromatograph. Determination of pesticide levels is quite important due to their effect on health and environment in fruit and vegetables. In this research, a new method of solid-phase microextraction has been established for organochlorine pesticide residues in strawberry and cucumber. In developed method, samples were treated with methanol:water (20%:80%) mixture and extracted with PDMS/ DVB fiber coating. The extracts were than injected to Gas Chromatography/ Mass Spectrometry (GC/ MS) and analysed in Split/ Splitless. HP5-MS column was used in GC/ MS and 18 pesticide mix.were formed with developed run programme. Method was validated and validation parameters were in acceptable range. Pesticides, correlation coefficients were found between (R2) were 0.92-0.99 with matrix matched calibration, recoveries were found between 63-99%, LOD were found between 0.245-0.493 µg/ L and relative standart deviations (RSD%) were lower than 20%.