Določanje neonikotinoidnih pesticidov v propolisu

magistrsko delo

Rok Tomšič (Author), Helena Prosen (Mentor), Iztok Turel (Thesis defence commission member), Irena Kralj Cigić (Thesis defence commission member), Ester Heath (Co-mentor)

Abstract

Namen magistrskega dela je bil razviti metodo za določevanje petih neonikotinoidnih pesticidov (acetamiprid, klotianidin, imidakloprid, tiakloprid, tiametoksam) v vzorcih propolisa. Preizkusil sem dva načina priprave vzorca: ekstrakcijo na trdno fazo (angl. SPE – Solid Phase Extraction) in QuEChERS ekstrakcijo (angl. Quick, Easy, Cheap, Effective, Rugged, Safe). Ekstrakte sem analiziral z LC-MS/MS instrumentom, ki je deloval v SRM načinu (angl. Selected Reaction Monitoring). Čistejše ekstrakte in boljše izkoristke sem dosegel z ekstrakcijo na trdno fazo, zato sem metodo SPE-HPLC-MS/MS tudi validiral. Validiral sem jo na dveh koncentracijskih nivojih (10 µg/L in 50 µg/L) s tremi ponovitvami na vsakem nivoju. Rezultati so pokazali, da daje metoda zadovoljive izkoristke (61 – 101 %) za vse analite razen za klotianidin, katerega izkoristek znaša 10 % v spodnjem in 20 % v zgornjem koncentracijskem nivoju. Ponovljivost metode je zadovoljiva, saj se relativni standardni odmiki gibljejo med 5 % in 29 % (spodnji koncentracijski nivo) ter med 3 % in 13 % (zgornji koncentracijski nivo). Za vse analite sem dosegel nizke meje zaznave (0,2 -4,4 µg/L) in meje določitve (0,8 – 14,7 µg/L). Zaradi kompleksne matrice vzorca sem za oceno matričnega efekta pripravil umeritveno premico z matričnimi raztopinami (angl. MM – Matrix Matched) in jo uporabil tudi za določitev linearnega območja in točnosti metode. Metoda je točna (relativna standardna napaka: 1,9 % – 10,4 %) ter linearna v širokem koncentracijskem območju (R2 > 0,991) za vse analite. SPE-HPLC-MS/MS metodo sem uporabil za analizo 30 realnih vzorcev propolisa (18 surovih vzorcev in 12 alkoholnih tinktur). V 7 vzorcih sem potrdil prisotnost acetamiprida, imidakloprida in tiakloprida nad mejo zaznave, vendar je bila njihova vsebnost pod mejo določitve optimizirane metode.

Keywords

neonikotinoidi;neonikotinoidni pesticidi;propolis;ekstrakcija na trdno fazo;SPE;QuEChERS ekstrakcija;analizne metode;tekočinska kromatografija visoke ločljivosti;HPLC;LC-MS/MS;magistrska dela;

Data

Language:	Slovenian
Year of publishing:	2019
Typology:	2.09 - Master's Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[R. Tomšič]
UDC:	543.393:638.135(043.2)
COBISS:	1538507459
Views:	731
Downloads:	259
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Analysis of neonicotinoid pesticides in propolis
Secondary abstract:	This study aimed to develop a method for the determination of five neonicotinoid pesticides (acetamiprid, clothianidin, imidacloprid, thiacloprid, and thiamethoxam) in propolis samples. Two sample preparation methods were tested: solid-phase extraction (SPE) and quick, easy, cheap, effective, rugged, and safe (QuEChERS). The extracts were then analysed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) in selected reaction monitoring (SRM) mode. Because solid-phase extraction resulted in cleaner extracts and better recoveries, only the SPE-HPLC-MS/MS method was validated. The method was validated at two spiking levels (10 µg/L and 50 µg/L) in triplicate at each level. Except for clothianidin, we obtained satisfactory recoveries the other four pesticides (61 % – 101 %). Recoveries of clothianidin were 10 % at the lower and 20 % at the higher spiking level, respectively. Method repeatability was also good with a relative standard deviation from 5 % to 29 % at the lower spiking level and from 3 % to 13 % at the higher spiking level. The method also showed low limits of detection (0.2 – 4.4 µg/L) and quantification (0.8 – 14.7 µg/L). In order to compensate for the matrix effect, matrix-matched calibration was used. Based on matrix-matched calibration curves, good accuracy (relative error: 1.9 % – 10.4 %) and linearity were determined (R2 > 0.991) for all of the neonicotinoids tested. The validated SPE-HPLC-MS/MS method was used to analyse 30 propolis samples (18 raw propolis and 12 alcohol tinctures). The presence of some analytes (acetamiprid, imidacloprid and thiacloprid) were above limits of detection in 7 samples, however their conectrations were lower than limits of quantification for optimised analytical method.
Secondary keywords:	neonicotinoids;SPE;QuEChERS;propolis;LC-MS/MS;
Type (COBISS):	Master's thesis/paper
Study programme:	1000375
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemija
Pages:	55 str.
ID:	11330971