Analysis of Residues in Environmental Samples

The state of the environment is very important for our lives and for that of future generations [...

DISAPPEARANCE OF PENDIMETHALIN IN SOIL AND ITS RESIDUE IN RIPE FENNEL

Disappearance of pendimethalin in soil, a herbicide widely used for control of weeds on vegetable crops, has been studied. A simple and rapid multiresidue analytical procedure for the quantifi cation of the substance has been applied using a Hewlett Packard 5890A gas chromatograph, equipped with a nitrogen – phosphorus detector (GC-NPD). Disappearance trend followed fi rst order kinetics seemed to be the best approximation. The average pendimethalin residues have decreased according to equations: y = 0.236e-0.0115x (exponential) and y = -0.0018x + 0.226 (linear) with excellent coeffi cient of determination in both cases. Half-lives obtained from those equations were 60 and 62 days, respectively. Low pendimethalin residue in plants indicate that fresh fennel may be used as additive in baby food. On the other hand, the experimental results indicate that pendimethalin is quite stable compound and may cause problems with follow-up crops

ZANIKANIE PENDIMETALINY W GLEBIE I JEJ POZOSTAŁOŚCI W KOPERKU

Disappearance of pendimethalin in soil, a herbicide widely used for control of weeds on vegetable crops, has been studied. A simple and rapid multiresidue analytical procedure for the quantifi cation of the substance has been applied using a Hewlett Packard 5890A gas chromatograph, equipped with a nitrogen – phosphorus detector (GC-NPD). Disappearance trend followed fi rst order kinetics seemed to be the best approximation. The average pendimethalin residues have decreased according to equations: y = 0.236e-0.0115x (exponential) and y = -0.0018x + 0.226 (linear) with excellent coeffi cient of determination in both cases. Half-lives obtained from those equations were 60 and 62 days, respectively. Low pendimethalin residue in plants indicate that fresh fennel may be used as additive in baby food. On the other hand, the experimental results indicate that pendimethalin is quite stable compound and may cause problems with follow-up crops.W pracy przedstawiono wyniki badań nad zanikaniem pendimetaliny w glebie. Pozostałości tej substancji oznaczano za pomocą chromatografu gazowego Hewlett Packard 5890A, wyposażonego w detektor azotowo – fosforowy (NPD). Przebieg zanikania początkowych pozostałości pendimetaliny najlepiej opisuje równanie kinetyczne pierwszego rzędu. Średnia jej zawartość w glebie obniżała się zgodnie z równaniem wykładniczym y = 0,236e-0,0115x i liniowym y = -0,0018x + 0,226. Okresy połowicznej przemiany wyznaczone na podstawie tych równań wyniosły odpowiednio 60 i 62 dni. W dojrzałym koperku pozostałości pendimetaliny wystąpiły na niskich poziomach a zatem świeży koperek uzyskany z pola odchwaszczanego za pomocą tego herbicydu może być stosowany do produkcji żywności dla dzieci

Physicochemical Parameters of Real Wastewater Originating from a Plant Protection Products Factory and Modification of the QuEChERS Method for Determination of Captan

The aim of this study was the modification and application of the QuEChERS method for the preparation and purification of samples in order to determine the level of captan in real wastewater originating from a plant protection products factory which was characterized by a significant content of organic substances [Chemical Oxygen Demand (COD) = 856 ± 128 mg O2/L and Total Organic Carbon (TOC) = 62 ± 9 mg/L]. The optimization of the method consisted of the selection of solvents used for the extraction of captan from wastewater and also sorbents used to purify the extracts by the dispersion of a solid phase extraction technique (dSPE). Two steps were used: extraction and clean-up. In the extraction step, acetonitrile was replaced by anacetonitrile:acetone mixture. In the clean-up step by the dSPE, five sorbents were tested: Florisil®, aluminum oxide (Al2O3), zirconium oxide (ZrO2), silicon oxide (SiO2) and PSA (primary and secondary amine). Concentrations of captan in wastewater extracts were determined by gas chromatography (GC) combined with electron capture detection (μECD). The best recovery parameters and precision of the method were obtained for samples purified using ZrO2 (recovery 98% and precision expressed as relative standard deviation RSD 8%) and Florisil® (recovery 96%, RSD 9%). Limits of detection (LOD) and quantification (LOQ) for determination of captan in diluted extract of wastewater were 0.003 and 0.01 mg/L, respectively. Matrix effects were in the range of −69% to −44% for samples purified by ZrO2 and Florisil®, respectively. The modified and optimized method was applied for fast and simple determination of captan levels in real industrial wastewater samples, in which the concentration of captan in diluted extract was determined to be 4.0 ± 0.3 mg/L

Simple Method for Fatty Acids Determination in Food, Superfood and Spice Samples by GC-MS Technique

The aim of the study was to modify and adapt to other matrices the fast and simple method for determining total lipid content expressed as fatty acid methyl esters (FAME) by performing the in situ transesterification. The primary method was published as a technical report for the FAME analysis in algae dry mass. Our modifications included the use of less toxic solvents, the use of an internal triglyceride standard and FAME determination by the gas chromatography technique coupled with the mass spectrometry technique in the Single Ion Monitoring mode (SIM). The modified method was validated for 37 fatty acids (saturated, monounsaturated and polyunsaturated) containing from four to twenty-four carbons in the carbon chain (C4-C24), and was adapted to five food matrices: three solids (yeast, yeast flakes, biscuits), and two liquids (milk thistle (Silybum marianum (L.) Gaertner) oil and olive oil). Additionally, 14 samples of spices and superfood samples, rich in unsaturated oils were analyzed. The validation parameters: linearity, precision, recovery, limits of detections and quantifications, were assessed and additionally Certified Reference Material of olive oil was analyzed

Characteristics of Dietary Fatty Acids Isolated from Historic Dental Calculus of the 17th- and 18th-Century Inhabitants of the Subcarpathian Region (Poland)

Dental calculus analysis can be a valuable source of archaeological knowledge, since it preserves not only microbial and host biomolecules but also dietary and environmental debris, as well as metabolic products likely originating from dietary and craft activities. Here we described GC-MS analysis of a set of historic dental calculus samples from the front teeth of the mandibles of seven individuals found in 17th- and 18th-century graves in the city of Rzeszow, located in South-eastern Poland. We have found that only saturated fatty acids, which are characteristic for fats of animal origin, were present in the tested samples. Our preliminary results indicate that the diet of modern-period inhabitants of Rzeszow was rich in animal products, such as meat and dairy products

A Miniaturized Sample Preparation Method for the Determination of Vitamins A and E in Food Products

A new analytical approach to the simultaneous identification and quantification of vitamins A and E in three representative matrices (Parmesan, spinach, and almonds) was developed. The analyses were based on high-performance liquid chromatography with UV-VIS/DAD detection. The procedure was optimized by a significant reduction in the weight of the tested products and quantities of reagents added during the saponification and extraction stages. A full method validation study was performed for retinol at two concentration levels (LOQ and 200 × LOQ), which showed satisfactory results, with recoveries ranging from 98.8 to 110.1%, and an average CV of 8.9%. Linearity was tested in the range of 1–500 µg/mL and showed the coefficient of determination R2 = 0.999. The satisfactory recovery and precision parameters were achieved for α-tocopherol (LOQ and 500 × LOQ) in the range of 70.6–143.2%, with a mean CV equal to 6.5%. The observed linearity for this analyte in the concentration range of 1.06–532.0 µg/mL was R2 = 0.999. The average extended uncertainties were estimated, using a top–down approach of 15.9% and 17.6% for vitamin E and A, respectively. Finally, the method was successfully applied to determine vitamins in 15 commercial samples

Essential Oils of Seven Lamiaceae Plants and Their Antioxidant Capacity

Oxidative stress has been reported as a cause of many diseases like Parkinson′s, Alzheimer′s, cardiovascular disease, and diabetes. Oxidative stress can also lead to cancer formation by promoting tumor development and progression. Antioxidants derived from Lamiaceae plants play an important role in natural medicine, pharmacology, cosmetology, and aromatherapy. Herein, we examine the antioxidative capacity of essential oils from seven aromatic Lamiaceae plants against the synthetic radicals DPPH and ABTS. Among the essential oils analyzed, the most robust scavenging capacities were found in mixtures of volatile compounds from thyme and savory. The scavenging activity of tested EOs against the ABTS radical was clearly higher than activity towards DPPH. Analysis of essential oils with weaker antioxidant activity has shown that volatile compounds from marjoram, sage, and hyssop were more active than EOs from lavender and mint. It can be suggested that the potent antioxidant capacity of thyme (Thymus vulgaris) and savory (Satyreja hortensis) are related to a high level of phenolic constituents, such as thymol and carvacrol. On the other hand, the elevated antioxidative power of marjoram, sage, and hyssop essential oils may also be due to their terpinene, o-cymene, terpinolene, and terpinen-4-ol constituents. Although non-phenolic components are less active than thymol or carvacrol, they may affect antioxidant capacity synergistically

Simultaneous Determination of Multi-Class Pesticide Residues and PAHs in Plant Material and Soil Samples Using the Optimized QuEChERS Method and Tandem Mass Spectrometry Analysis

New analytical approaches to the simultaneous identification and quantification of 94 pesticides and 13 polycyclic aromatic hydrocarbons (PAHs) in five representative matrices (pepper, apple, lettuce, wheat, and soil) were developed. The analyses were based on gas chromatography coupled with triple quadrupole tandem mass spectrometry (GC-MS/MS). The procedure was optimized by changing the solvent used during the extraction, from acetonitrile to the acetone: n-hexane mixture at a volume ratio of 1:4 (v/v), as well as the use of a reduced amount of water during the extraction of compounds from cereals. An additional modification was the use of florisil instead of GCB in the sample cleanup step. A full method validation study was performed, at two concentration levels (LOQ and 1000 × LOQ), which showed satisfactory results for all analytes from the PAHs group, with recoveries ranging from 70.7–115.1%, and an average RSD of 3.9%. Linearity was tested in the range of 0.001–1.000 mg/kg and showed coefficients of determination (R2) ≥ 0.99 for all PAHs. Satisfactory recovery and precision parameters (LOQ and 100 × LOQ) were achieved for almost all analytes from the pesticide group in the range of 70.1–119.3% with the mean RSD equal to 5.9%. The observed linearity for all analytes in the concentration range of 0.005–1.44 mg/kg was R2 ≥ 0.99, with the exception of famoxadone, chizalofop-p-ethyl, prothioconazole, spirodiclofen, tefluthrin, and zoxamid. The extended uncertainties were estimated, using a top-down approach of 9.9% (average) and 15.3% (average) for PAHs and pesticides samples, respectively (the coverage factor k = 2, the 95% confidence level). Ultimately, the method was successfully applied to determine pesticide residues in commercial samples of fruit, vegetables and grain, and soil samples for PAHs, which were collected from selected places in the Podkarpacie region. A total of 38 real samples were tested, in which 10 pesticides and 13 PAHs were determined. Proposed changes allow us to shorten the sample preparation time (by 20%) and to reduce the consumption of organic solvents (by 17%). The use of florisil for sample cleanup, instead of GCB, improves the recovery of compounds with flat particles