Primena tečne hromatografije sa DAD detektorom za određivanje ostataka acetamiprida i 6-hlornikotinske kiseline u uzorcima trešanja

A rapid and simple method for simultaneous determination of acetamiprid and its metabolite 6-chloronicotinic acid in sweet cherry samples has been developed. This residue analysis method is based on the reversed phase separation on C18 column with gradient elution. Analytes' determination and quantification were performed by high performance liquid chromatography (HPLC) with diode-array detector and chromatograms were extracted at 230 nm. Extraction efficiency experiments demonstrated the ability of this method to extract neonicotinoids from sweet cherry samples. These insecticides were extracted with a mixture of acetonitril/0.1N ammonium-chloride (8/2, v/v). The average recoveries of acetamiprid and 6-chlornicotinic acid from sweet cherry samples were in the range of 95-101% and 73-83%, respectively, with the associated relative standard deviations (RSDs) lt 5%. Expanded measurement uncertainties for the analyzed compounds were 2.7 and 3.01%. The limit of quantification (LOQ) was 10 μg/kg and 30 μg/kg for acetamiprid and 6-chloronicotinic acid, respectively. Thus, the developed HPLC/DAD method can be considered a useful tool for sensitive and rapid determination of acetamiprid and 6-chloronicotinic acid. Hence, the method may find further application in the analysis of real sweet cherry samples contaminated with these insecticides at a ppb level.U radu je predstavljena jednostavna metoda za određivanje acetamiprida i njegovog metabolita, 6-hlornikotinske kiseline, u uzorcima trešanja. Metoda je bazirana na primeni reverzno-faznog razdvajanja na C18 koloni primenom gradijentnog eluiranja. Određivanje i kvantifikacija analita je vršena tečnom hromatografijom (HPLC) sa DAD detektorom, pri čemu je korišćena talasna dužina od 230 nm. Tačnost metode je ocenjena procenom merne nesigurnosti. Ekstrakcija acetamiprida i 6-hlornikotinske kiseline iz uzoraka trešanja je vršena smešom acetonitril/amonijum-hlorid (0,1N) u odnosu 80:20 (v/v). Sva merenja su vršena u tri ponavljanja, pri čemu su dobijeni prinosi određivanja acetamiprida i 6-hlornikotinske kiseline u rasponima 95-101% i 73-83%, respektivno. Relativne standardne devijacije (RSD) merenja su u svim slučajevima bile ispod 5%. Limiti kvantifikacije za acetamiprid i 6-HNK iznosili su 10 i 30 μg/kg, respektivno. Kombinovana merna nesigurnost rezultata analize acetamiprida i njegovog metabolita procenjena je na 1,35, odnosno 1,50%, a proširena na 2,7 i 3,01%, upotrebom faktora pokrivanja (k=2) koji odgovara nivou poverenja od 95%, za normalnu raspodelu. Nakon validacije i procene merne neizvesnosti dobijeni rezultati pokazuju da se razvijena HPLC/DAD metoda može primeniti za određivanje sadržaja acetamiprida i 6-hlornikotinske kiseline u uzorcima trešanja i relevantnim matriksima kontaminiranim ovim jedinjenjima

Validation of analytical method for determination of terbuthylazine and S-metolachlor residues in soil

Terbuthylazine and s-metolachlor are commonly used herbicides, especially after prohibition of some other triazine and chloracetanilide herbicides. However, often used pesticides pose the risk of soil contamination due to their persistence, toxicity and bioaccumulation. The trace determination of herbicide residues, generally in environmental samples, presents a challenging analytical problem. The present work was carried out to analyze terbuthylazine and s-metolachlor residues in soil based on high performance liquid chromatography (HPLC), and QuEChERS extraction method. The method was optimized and validated according to the parameters of precision, accuracy, linearity, limits of detection and limits of quantification. Analysis was carried out using an HPLC-UV diode array detection system (Agilent 1100, USA), with an Agilent Zorbax Eclipse C18 column (50 mm × 4.6 mm, 1.8 μm) and mobile phase consisting of ultrapure water and acetonitrile (55/45, v/v). Mean recoveries obtained from soil samples fortified at three different levels ranged from 81 to 92%. The method detection limits ranged from 0.01 to 0.05 mg kg-1 . Obtained results completely fulfilled the SANCO/825/00 rev. 8.1 16/11/2010 criteria

Sulfonylurea herbicides residues analysis in soil

Prosulfuron, rimsulfuron, thifensulfuron-methyl and tritosulfuron are widely used sulfonylurea herbicides (SUs), applied in low-dose rates. However, these herbicides under specific conditions as low temperature, poor rainfall, microbial activity. high pH of soil, can remain at low concentrations in soil and can affect the growth of sensitive plants. This paper presents the method that we developed for determination of prosulfuron, rimsulfuron, thifensulfuron-methyl and tritosulfuron residues in soil. Determination and quantification were performed by HPLC/DAD using Agilent Zorbax SB-C18 column (3.0 mm*250 mm. 5 um particle size). Mobile phase was acetonitrile/0.1% CH3COOH solution. Analyzed SUs showed linear calibrations from 0.05 to 0.2 mg/ml with correlation coefficient (1°) above 0.990%. The recovery data were obtained by spiking blank soil samples at two concentration levels (2.5-5.0 mg/kg), yielding average recovery between 95.56 and 99.79%. Precision values expressed as relative standard deviation (RSD) were between 0.91-1.11% for all SUs herbicides for the intraday precision. Considering the obtained values of analytical parameters, the proposed method proved to be an efficient and sensitive method for the determination of prosulfuron, rimsulfuron, thifensulfuron-methyl and tritosulfuron in soil samples

Method for the determination of triclopyr residues in soil

In this study, a method for the determination of triclopyr in soil samples has been developed. The analyte was extracted with acidified acetonitrile, while the determination and quantification of triclopyr were performed by high-performance liquid chromatography (HPLC) with a diode array detection. Optimal HPLC-DAD conditions were: mobile phase acetonitrile and 0.1% H3PO4 (50:50), the flow rate of 0.9 ml/min, and 220 nm of wavelength. In terms of method validation, accuracy (expressed as recovery), linearity, precision (RSD) and LOQ were determined. Obtained results for the recovery using this method, at the three spiking levels, were 81-93%. Precision, expressed as RSD, was 9.1%, while the LOQ was 0.01 mg/kg. Therefore, it can be concluded that the proposed method could be applied for the analysis of triclopyr residues in the soil samples

Simultaneous determination of mesotrione and nicosulfuron in OD formulations

In this study an isocratic high-performance liquid chromatographic method with diode array detection was developed for simultaneous determination of mesotrione and nicosulfuron active ingredients content in pesticide products formulated as oil dispersion (OD). For the analysis, LC system an Agilent Technologies 1100 was used. Good separation was achieved on a Zorbax SB-C18 column using a mobile phase consisting of 0.1% CH3COOH/acetonitrile (75:25), at a flow rate of 0.9 ml/minute and UV detection at 245 nm. Column temperature was 40 °C, injected volume was 1 µl. Retention times for nicosulfuron and mesotrione were 3.009 min and 4.363 min, respectively. Validation of the method was performed according to IAEA guidelines. The obtained results showed that the linear coefficients were 0.9999 for both analyzed herbicides in the mixture. The repeatability of the method expressed as relative standard deviations (%RSDr) was 0.33% for mesotrione and 0.18% for nicosulfuron. The accuracy of the proposed method was determined from recovery experiments. The obtained results for mesotrione and nicosulfuron were 100.5-102.9% and 99.3-103.9%, respectively, proved to be acceptable. Precision of the method expressed as %RSD was 0.38% for mesotrione and 0.99% for nicosulfuron and are lower than the values calculated by the Horwitz equation

Razgradnja acetamiprida u plodovima trešanja

Degradation of acetamiprid in sweet cherry samples was evaluated at several intervals from the product application until the end of the pre-harvest interval. An orchard of sweet cherries located at Stepanovićevo village near Novi Sad was used in this study. Acetamiprid was applied according to the manufacturer's recommendation for protecting sweet cherries from their most important pests. Sweet cherry fruit samples were collected at eight intervals: immediately after acetamiprid application and 2, 4, 6, 8, 10, 12 and 14 days after application. The extraction of acetamiprid from sweet cherry samples was performed using a QuEChERS-based method. Determination was carried out using an HPLC-UV diode array detection system (Agilent 1100, United States) with an Agilent Zorbax Eclipse C18 column (50 mm × 4.6 mm internal diameter, 1.8 μm particle size). The method was subjected to a thorough validation procedure. The recovery data were obtained by spiking blank sweet cherry samples at three concentration levels (0.1-0.3 mg/ kg), yielding 85.4% average recovery. Precision values expressed as relative standard deviation (RSD) were below 1.61% for the intraday precision. Acetamiprid showed linear calibrations from 0.05 to 2.5 μg/ml with correlation coefficient (R2) of 0.995%. The limit of detection and limit of quantification were found to be 5 μg/kg and 14 μg/kg, respectively. The validated method was applied in the analysis of acetamiprid in sweet cherry samples. During the study period, the concentration of acetamiprid decreased from 0.529 mg/kg to 0.111 mg/kg. The content of acetamiprid in sweet cherry samples at the end of the pre-harvest interval was below the maximum permissible level specified by the Serbian and EU MRLs.U cilju praćenja razgradnje acetamiprida u plodovima trešanja u periodu od primene preparata do isteka karence, izvršen je tretman preparatom na bazi ove aktivne materije u preporučenoj dozi. Ogled je postavljen u zasadu srednje kasne sorte trešnje na lokalitetu Stepanovićevo u okolini Novog Sada. Plodovi su uzorkovani osam puta - odmah nakon primene preparata, 2, 4, 6, 8, 10, 12 i 14 dana. Ekstrakcija acetamiprida iz trešanja izvedena je QuEChERS metodom. Za određivanje acetamiprida korišćena je tečna hromatografija sa DAD detektorom (Agilent 1100, United States) i Agilent Zorbax Eclipse C18 kolonom (unutrašnji prečnik 50 mm x 4.6 mm, veličina čestica 1.8 μm). Kao mobilna faza upotrebljeni su acetonitril i 1.5% rastvor CH3COOH (30/70), sa protokom 1 ml/min, temperaturom kolone 25 oC i injektovanom zapreminom 2,5 μl, dok je kao odgovarajuća talasna dužina usvojena vrednost od 254 nm. Validacija metode je u potpunosti sprovedena u skladu sa zahtevima standarda SANCO/12495/2011 (EU Commission Health and Consumer Protection Directorate- General, 2011). Prosečna vrednost prinosa ekstrakcije acetamiprida iz trešanja proverena na tri nivoa obogaćenja (0.1-0.3 mg/kg) iznosila je 85.4%. Preciznost merenja razmotrena proverom ponovljivosti određivanja acetamiprida izražena je relativnom standardnom devijacijom (RSD) sa vrednošću manjom od 1.61%. U opsegu masenih koncentracija acetamiprida od 0,05 do 2,5 μg/ml postignuta je dobra linearnost odziva detektora sa koeficijentom varijacije od 0,995%. Limit detekcije i kvantifikacije za određivanje acetamiprida u trešnjama prikazanom metodom iznose 5 μg/kg i 14 μg/kg. Tokom ispitivanog perioda koncentracija acetamiprida u trešnjama se smanjivala od 0,592 mg/kg neposredno nakon primene insekticida do 0,111 mg/kg po isteku karence od 14 dana. Analizom je utvrđeno da je sadržaj acetamiprida u uzorcima plodova trešnje nakon isteka perioda karence ispod maksimalno dozvoljene količine za ovu aktivnu materiju propisane Pravilnikom Republike Srbije (0,2 mg/kg) i Evropske Unije (1,5 mg/kg)

Determination of clindamycin in pig plasma after implantation of poly(D,Llactide-co-glycolide)/hydroxyapatite/clindamycin core–shell nanosphere by liquid chromatography-tandem mass spectrometry

Clindamycin was determined in pig plasma by liquid chromatography/tandem mass spectrometry (LC-MS/MS). The multiple reaction monitoring (MRM) mode of precursor-product ion transitions for clindamycin (m/z=421.1/126.1) and the internal standard, caffeine (m/z=192/125) was used. The samples were prepared by two methods: 0.1% formic acid in methanol and 1.5% trichloacetic acid. The recovery for the two preparation methods at 0.05mg/ml (n=6) was found to be for the first 104.3% and for the second method 106.5%, with repeatability RSD 1.1% and RSD 4.34%, respectively. The results of the comparison of the two different preparation methods of samples demonstrated that both methods were satisfactory

The use of cultivated plants in water quality monitoring

Water contamination is the most complex global environmental problem. Any pollution that is emitted into the environment at a certain time reaches the groundwater, rivers, lakes and seas. Nowadays aquatic ecosystems around the world are increasingly threatened by different pollutants. Rivers and lakes are under constant pressure from urban wastewater pollution, chemical waste from industry and transport, pesticides from agricultural areas, etc. By applying various methods in the laboratory were tested quality and impact of the water, characteristic for its high content of certain pollutants, to the test plants: buckwheat (Fagopyrum esculentum) and cabbage (Brassica oleracea). The analyzed water was taken from two locations of the River Lesa in Portugal. Physico-chemical analysis of water indicates that nitrates, nitrites and ammonium were detected in values exceeding maximum allowable concentration, according to Portuguese regulations of water quality. Also, in the analyzed water samples cadmium (Cd), magnesium (Mg) and iron (Fe) were found in quantities that exceed the MAC values, as well as some pesticidal substances (MCPA, fonofos). In the tested samples, long list of pharmaceuticals were detected. The obtained results indicate differences in tolerance of the test plants according to the parameters which have been detected in the water. Physiological parameters (germination energy and germination) have not been proven to be good indicators of water quality, while the more reliable may be considered some morphological parameters (length of shoot), that reacted by stimulation of the shoot

From the Gregor Mendel’s garden to a molecular marker lab: cutting edge of breeding grain and forage crucifers in Serbia

A complex and strategically structured research on oil-rich grain, vegetable and forage crucifers at the Institute of Field and Vegetable Crops in Novi Sad (IFVCNS) is based upon maintaining and sustainably utilising the germplasm collections of each crop. It comprises conventional and molecular breeding, biotechnology, agroecology, physiology, biochemistry, agronomy and seed science as well as commercial production for local and international markets. Here, we shall focus on oil-rich grain and forage crops, namely rapeseed, black and white mustards, forage kale and false flax. All collected accessions of our collection were phenotypically and cytogenetically characterized, including the monitoring and examining flower morphology, pollen features and number of chromosomes. The Mendel's rules are the basis of all the methods in breeding cultivars and hybrids of oil and forage crucifers. Constant and systematic use of these fundamental genetic postulates has led to the development and official registration of 13 autumn-sown rapeseed cultivars and two hybrids, two spring-sown rapeseed, one black mustard, one oil-rich grain white mustard, three autumn-sown forage kale and one spring-sown forage white mustard cultivar, as well as two false flax lines. Today, the conventional breeding methods are closely followed by various molecular genetic tools. So far, the most prominent role in assisting the selection of the genotypes with desirable traits has been played by RAPD and SSR molecular markers. A well-designed and feasibly organized integration of the Mendel's rules, conventional breeding methods and molecular breeding tools are anticipated as significantly improving the existing programmes. It ensures that the future efforts will yield further progress in oil and forage crucifers’ research. This will benefit to various aspects of economy, especially the environment friendly production of quality oil for both human consumption and non-food industry and low-input and esteemed forage in ruminant feeding

The crude protein content in alfalfa grown on different soil types

Alfalfa (Medicago sativa L.) is the most important forage legume. Crude protein content is one indicator of the its quality, which, among other things, is affected by the variability of soil properties. The aim of this study was to determine the effect of different soil types on the content of crude protein in alfalfa. The examination was conducted on six types of soil: chernozem, vertisol, eutric cambisol, humofluvisol, fluvisol and humogley (according to domestic soil classification). Sampling of plant material was carried out during May 2011., in the second year of alfalfa production. On the basis of these results it can be concluded that there are statistically significant differences in the content of crude protein between alfalfa plants, grown on different soil types. The highest protein content has alfalfa grown on chernozem (26.28%) and lowest on the eutric cambisols (13.98%). Soils, on which the protein content in alfalfa was higher, are characterized by good physical and chemical properties, a higher content of total nitrogen, primarily nitrogen fixation increased, as have the favorable conditions for microbial activity. This is primarily related to the pH value, because the greatest number of Rhizobium is in neutral and slightly alkaline soils. The expected results should be a guideline for the production practice, because the modeling of feed production, in different production conditions, raises the possibility of more intensive crop and livestock production