The increasing global population and food security concerns are rapidly raising the demand for sustainable approaches to increasing agricultural productivity. Triacontanol (TRIA) is a non-toxic primary alcohol that can be naturally obtained from plant waste and has regulatory effects on growth, yield, and physiological processes in plants. Investigating the contribution of such natural growth regulators, which are low-cost and accessible to farmers, to yield increase in potato farming is of great importance for sustainable agriculture. This study was conducted in a total of 270 pots under greenhouse conditions using a randomized block design with 5 different TRIA doses, 6 different application methods (control, IAA, SA, GA3, ABA, and mix) and 3 different application approaches (foliar, soil, and soil + foliar). The study aimed to determine the effects of TRIA on the Agria potato variety (Solanum tuberosum L.) and to identify the most effective combination of application methods for yield enhancement. According to the results, foliar application of TRIA at a dose of 10 µM yielded the most effective outcomes compared to other methods and doses. Under greenhouse conditions, foliar-applied 10 µM led to a 122.97

Abstract Antioxidants play a role in the transformation of free radicals into more stable chemical structures. Work on phenolic antioxidants has accelerated in recent years. Curcumin is a natural phenolic with antioxidant properties. In this study, a salt-supported homogenous liquid-phase microextraction method was used for preconcentration and spectrophotometric determination of curcumin for the first time. The curcumin was transferred into the organic phase using cyclohexylamine as the extraction solvent at pH values between 2.0 and 7.0 and determined by spectrophotometry. The results showed that the performance of the method for curcumin was unaffected by pH. The pH of the sample solution, the mass of salt, and the volume of the solvent were optimized, and the influence of the matrix types was investigated. The limits of detection and quantification were 1.44 and 4.80 µg L−1 for curcumin. The developed method was employed for the analysis of food samples.

Abstract Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic that may degrade human health. Organic solvents are commonly used for the extraction of PAHs from solid samples and the analytes are determined chromatographically. This study describes the ultra-high performance iquid chromatography-diode array detection (UHPLC-DAD) determination of PAHs in sewage sludge and compost used as agricultural fertilizer. The PAHS may be transmitted to humans through the food chain. Analytes in the fertilizer were quantitatively extracted into the organic phase in water-dichloromethane-acetonitrile and determined liquid chromatographically. 16 PAHs were selectively extracted in a single clean-up step. For method development, the type and volume of organic solvent, pH of the water, and ultrasonic extraction time were optimized. For method validation, analytical figures of merit were obtained for the linearity, limit of detection (LOD), limit of quantification (LOQ), stability, intra- and inter-day precision, and accuracy. The developed and validated method was used for PAH determination in the fertilizers. Sample analyses were performed with 89–102% recovery values and 0.7–4.1% relative standard deviations.

PAHs are carcinogenic compounds that threaten human health. Organic solvents are usually used for extraction from solid samples and they are determined chromatographically. This study is related to the UHPLC-DAD determination of PAHs, which are found in swedge sludge and compost samples used as fertilizer in agriculture, and which are transmitted to humans through the food chain. Analytes in the fertilizer samples were quantitatively extracted into the organic phase in water-dichloromethane-acetonitrile dispersion medium and liquid chromatographically determined. 16 PAHs were selectively extracted in a single and without extra clean up step. For method development, analytical parameters like type and volume of organic solvent, pH of the water, and ultrasonic extraction time were all optimized. For method validation, implementations were performed for linearity, limit of detection (LOD), limit of quantification (LOQ), stability, intra- and inter-day precision and accuracy. The developed and validated method was used for PAHs analysis in the fertilizers. Sample analyses were performed with 89–102% recovery rates and 0.7-4.1% RSD.

A study, where uraniumwas online enriched and laser diode spectrometrywas determined, was performedwith some bottledmineralwater samples. A uranium-imprinted polymer (PMDU) was synthesized and characterized for preparation of a specific adsorbent of UO22+ cations. The homemade system preconcentrated uranium in PMDU resin and determined using an Arsenazo III complex at 650 nm in a combined laser diode spectrometer. All analytical parameters of the system were optimized at 5.5 of the retention pH, 6.0 N HClO4 of eluent concentration, 0.05% of Arsenazo III complex, and a 40 mm coil length. The effect of interferent ions was also investigated and LOD and LOQ values were found to be 0.54 and 1.80 ng mL(-1) respectively. Sample throughput was 12 h(-1), the preconcentration factor was 50, and RSD% value was 1.1. Certified reference materials of TMDA 52.3 and TMDA 62.2 were quantitatively analyzed and the proposed method was successfully applied to the bottled mineral water samples. (c) 2020 Elsevier B.V. All rights reserved.

This method was developed for the determination of trace amounts of aluminum(III) in dialysis concentrates using atomic absorption spectrometry after coprecipitation with lanthanum phosphate. The analytical parameters that influenced the quantitative coprecipitation of analyte including amount of lanthanum, amount of phosfate, pH and duration time were optimized. The % recoveries of the analyte ion were in the range of 95-105 % with limit of detection (3s) of 0.5 µg l-1. Preconcentration factor was found as 1000 and Relative Standard Deviation (RSD) % value obtained from model solutions was 2.5% for 0.02 mg L-1. The accuracy of the method was evaluated with standard reference material (CWW-TMD Waste Water). The method was also applied to most concentrated acidic and basic dialysis concentrates with satisfactory results.

A new separation and pre-concentration method for spectrophotometric determination of glyphosate herbicide was developed. Glyphosate was converted into dithiocarbamic acid with CS2, followed by copper in the presence of ammonia to promote complex formation. This complex was collected in a CH2Cl2 organic drop and absorbance measured at 435nm. The analytical parameters, such as the amount of NH3, Cu(II) and CS2, type of extraction solutions, and the ratio of dispersive and organic liquids were optimized. The calibration curve was linear in the range 0.5-10mgl-1. The limits of detection and quantification were calculated from 3s to 10s criterions as 0.21mgl-1 and 0.70mgl-1, respectively. The developed method was applied to legume samples with the satisfactory recovery values of 98±4-102±3%.

3,5 - Dimethylpyrazolium glyceroborate is a nitrification inhibitor (a member of pyrazole derivatives) used for the fixation of nitrogen into the soil. In this study, an HPLC-DAD method was developed and validated for determination of 3,5 - dimethylpyrazole in order to determine 3,5 - dimethylpyrazolium glyceroborate in fertilizer samples. For method development, analytical parameters like type of eluent solution and column filling material and device parameters like eluent flow rate, column oven temperature and measurement wavelength were all optimized. For method validation, implementations were performed for linearity, limit of detection (LOD), limit of quantification (LOQ), specificity, stability, intra- and inter-day precision and accuracy. The developed and validated method was used for inhibitor detection in nitrogenous fertilizers. Sample analyses were performed with 95.6-103.3% recovery rates and 0-4.61% relative errors.

A new and rapid on-line flow injection (FI) procedure for the preconcentration and separation of aluminum(III) species in dialysis concentrates is described based on the combining of solid phase extraction with Lewatit TP-207 resin and electrothermal atomic absorption spectrometry (ETAAS). Lewatit TP-207 resin being a weakly acidic, macroporous cation exchanger with chelating iminodiacetate groups was firstly used in the determination of Al(III) species. The influences of the analytical parameters such as pH, type of eluent, flow rates of the eluent and sample, volume of the eluent, and matrix ions were investigated. A preconcentration factor of 40 and a detection limit (LOD, defined as 3s/b) of 7.4ngL−1 were achieved along with the sampling frequency of 21h−1, a sample loading time of 170s, and a sample consumption of 2.8mL. The relative standard deviation (RSD) was 2.1% for 1μgL−1 Al(III) level. The developed method was performed for the determination of Al(III) in dialysis concentrates. The results of the analysis of the certified reference material (CRM 403) are in good agreement with the certified value.

A rapid and simple on-line method is described for the determination of Au(III) in various samples. The method is based on the sorption of gold(III) on Lewatit MonoPlus TP207 chelating resin including the iminodiacetate group, which is used as sorbent material and packed in a minicolumn. The chemical variables such as the pH of the sample solution, eluent type, interfering ions and concentrations of reagents, and instrumental variables such as sample loading volume, reagents flow rates, and tubing length, which affect the efficiency of the method were studied and optimised. Au(III) was sorbed on the chelating resin, from which it could be eluted with 3 mol L-1 HCl, and then introduced directly to the nebuliser-burner system of FAAS. The limit of detection of the method was 0.2 mu g L-1 while the relative standard deviation was <4.0% for 20 mu g L-1 Au(III) concentration. The preconcentration factor was found to be 106 while the optimised sample volume was 15.3 mL. The accuracy of the method was verified by analysing the certified reference material. The developed method was applied successfully for the determination of gold in different samples with satisfactory results.

In this study, the concentration-dependent joint action of chromium (Cr) and salt (NaCl), two important environmental stressors, was examined in aquatic plants. Ceratophyllum demersum L. plants were exposed to Cr (0–10 mM) for 5 days in the presence and absence of NaCl (0–500 mM). The effect of Cr, Na, and Cl accumulations on certain biological parameters (water content, ion leakage, relative growth rate, photosynthetic pigments, and protein and proline contents) was determined. Furthermore, the interactive effects of NaCl and Cr were evaluated using a mathematical model developed on the basis of the theory of probabilities. The highest Cr accumulation (0.42 mmol g−1) was found in plants treated with 10 mM Cr + 125 mM NaCl. Treatment with 125 mM NaCl resulted in an increase in Cr accumulation compared with that in the control. However, 250 and 500 mM NaCl concentrations decreased Cr accumulation. Proline and water contents were not affected by increasing Cr concentration. However, NaCl did have a significant effect on any of the studied parameters. Furthermore, the interactive effects of Cr and NaCl on all studied parameters except for proline and water contents were determined. Except for photosynthetic pigments and proline content, effect of NaCl was higher than Cr on all studied parameters. The interactive effects were mostly antagonistic or additive. However, the mode of action for ion leakage was synergistic or additive. These results suggest that the coexistence of NaCl and Cr in aquatic ecosystems does not pose an additional ecological risk for aquatic plants.

A new on-line separation/preconcentration system was developed for the determination of Cu(II) ions by flame atomic absorption spectrometry in urine samples. A newly synthesized chelating resin, by anchoring eriochrome blue black R reagent to Amberlite XAD-16 resin, was used as a packing material for the selective separation/preconcentration of Cu(II) ions. The influence of the parameters on the determination of Cu(II) ions such as pH of sample solution, amount of the resin, eluent type, interfering ions and flow variables was studied. The detection limit of the method was 1.0 μg L(-1) while precision was 2.3% (n=15) at 50 μg L(-1) Cu(II) level. The adsorption capacity of the resin was 217 μg g(-1) Cu(II). The accuracy of the method was proven using TMDA-64 standard lake water and synthetic urine sample. The developed method has been applied successfully to the determination of copper in urine with satisfactory results.

A simple and reliable method for separation/preconcentration of Ag(I) by using 5-(p-dimethylaminobenzylidene) rhodanine reagent and Sepabeads SP207 adsorbent prior to its determination by flame atomic absorption spectrometry (FAAS) was developed. The optimum pH of the method for separation/preconcentration of Ag(I) was found to be 4.0. The preconcentration factor was 200. The limits of detection and quantification of the method were 0.13 and 0.44 mu g L-1, respectively. Relative standard deviation and adsorption capacity were 1.0% and 5.40 mg g(-1), respectively. The recovery of Ag(I) at pH 4.0 with 50 mg resin was quantitative without interferences caused by alkaline and alkaline earth cations, presenting concentrations of up to 10000 mu g mL(-1), except for K+. The accuracy of the method was checked by analysing TMDA-70 lake water certified reference material and by addition-recovery experiments. The method was applied for the determination of Ag(I) in tap water, mineral water, sea water, anode slime, rock and cream samples.

A new on-line flow injection (FI) procedure for the sequential separation, preconcentration and speciation of Cr(III)/Cr(VI) species in different matrices is described based on the combining of solid phase extraction and flame atomic absorption spectrometry (FAAS). Poly 2-(5-methylisoxazol)methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinyl-benzene and Dowex 21K resins were used as chelating and ion-exchange materials for the separation/preconcentration of Cr(III) and Cr(VI) ions, respectively. Trace amounts of chromium retained on the resins were eluted sequentially with HNO3 and then introduced directly to the nebulizer-burner system of FAAS. The optimum conditions such as pH of the sample solution, amount of the resin, volume of the sample and interfering ions, which are effective on the quantitative recovery of the analytes, were investigated for sequential determination of Cr(III) and Cr(VI) ions. The preconcentration factors were found to be 48 and 30 for Cr(III) and Cr(VI), and the detection limits corresponding to three times the standard deviation of the blank (3s/b) were 0.05 and 0.3µgL−1, respectively. The method was verified by analyzing a certified reference material. The proposed method was applied to the determination based on the speciation of chromium in various real samples with satisfactory results.

A simple on-line separation/preconcentration procedure is described for the determination of trace levels of Pb(II) by flame atomic absorption spectrometry (FAAS). A mini-column packed with Dowex Marathon C (DMC) ion-exchange resin was used for the on-line preconcentration of Pb(II) at pH 3.5. Pb(II) was sorbed on the resin, from which it could be eluted with 3 mol L−1 HCl and then introduced directly to the nebulizer–burner system of FAAS. The parameters influential on the determination of Pb(II) ions such as the pH of sample solution, eluent type, interfering ions and flow variables were studied. Under the optimum conditions, the calibration graph obtained was linear over the concentration range of 0.01–0.1 mg L−1. The detection limit of the method was 1.3 μg L−1 while precision was 1.1% (n = 15) at a 0.05 mg L−1 Pb(II) level. The accuracy of the method was proven using standard reference materials. The developed method has been applied successfully to the determination of lead in water and various environmental samples with satisfactory results.

An on-line flow injection pre-concentration-flame atomic absorption spectrometry method was developed to determine trace zinc in water (tap, dam, and well water), biological (hair and nail), and liver samples. As a solid phase extractant, a synthesized new chelating resin, poly(2-thiozylmethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was used. The resin was characterized by Fourier transform infrared spectroscopy, elemental analysis, and surface area by nitrogen sorption. A pre-concentration factor of 40-fold for a sample volume of 12.6 mL was obtained by using the time-based technique. The detection limit for the pre-concentration method was found to be 2.2 μg L(-1). The precision (as RSD,%) for 10 replicate determinations at the 0.04 μg mL(-1) Zn concentration was 1.2%. The calibration graph using the pre-concentration system for zinc was linear with a correlation coefficient of 0.998 in the concentration range from 0.005 to 0.05 μg mL(-1). The applicability and accuracy of the developed method were estimated by the analysis spiked water, biological, liver samples (83-105%), and also certified reference material TMDA-70 (fortified lake water) and SPS-WW1 Batch 111-Wastewater. The results were in agreement with the certified values.

A method was developed for the on-line determination of palladium in complex matrices with flame atomic absorption spectrometry (FAAS) using Amberlite XAD-16 resin functionalized with 2-[2-(5-thiol-1,3,4-thiadiazolyl)]-azonaphthol (TTAN) reagent. Optimum experimental conditions such as pH of sample, type of eluent, amount of resin, volumes of sample and eluent solution, flow rates of sample and eluent, and effect of interfering ions were established. A 0.1molL(-1) thiourea solution in 0.5molL(-1) HCl was used as the eluent and subsequently transportation the analyte ions into the nebulizer-burner system for atomization. The synthesized chelating resin material showed excellent chemical and mechanical resistance, fast adsorption kinetics permitting the use of high sample flow rates without significant losses of retention efficiency. The detection limit of the method was 1.5 mu gL(-1) while the relative standard deviation (RSD%) was 2.4% at 0.1mgL(-1) Pd(II) level. The developed method was successfully applied to the determination of palladium in the catalytic converter and water samples.

On-line preconcentration procedures for the determination of Ag(I) and Pd(II) by flame atomic absorption spectrometry have been described. A new chelating resin, poly (N,N′-dipropionitrilemethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was synthesized and used as a new adsorbent material. The resin was characterized by Fourier transform infrared spectroscopy and elemental analysis. Ag(I) was adsorbed on the chelating resin at pH 5.0 and eluted with 1.0molL−1 HNO3. Pd(II) was retained at pH 9.5 and eluted with 1.5molL−1 HCl. The experimental parameters (pH, type and concentration of eluent, flow rates of sample and eluent solutions, elution time and the effect of interfering ions) for both Ag(I) and Pd(II) were investigated in detail. The detection limit for Ag(I) was 2.4μgL−1 and the relative standard deviation was 2.9% for 0.2μgmL−1 Ag(I). The detection limit for Pd(II) was 1.7μgL−1 and the relative standard deviation was 2.8% for 0.3μgmL−1 Pd(II). Accuracy was confirmed by analyzing a certified reference material (TMDA-70), recovery studies on real samples and comparison with electrothermal atomic absorption analysis. The proposed methods were successfully applied to the on-line determination of Ag(I) in bottled water, pharmaceutical cream and anode slime samples and Pd(II) in bottled water and catalytic converter samples.

A simple and reliable on-line separation/preconcentration procedure was developed for the determination of trace levels of Ag(I) by flame atomic absorption spectrometry. Poly[N-(3-methyl-1H-indol-1-yl)-2-methacrylamide-co-2-acrylamido-2-methyl-1-propane sulfonic acid-co-divinylbenzene] was synthesized and characterized as a new chelating resin for the first time. Ag(I) was sorbed on the chelating resin, from which it could be eluted with 3 mol L−1 HCl and then introduced directly to the nebulizer-burner system for flame atomic absorption spectrometry. The parameters influential on the determination of Ag(I) ions such as the pH of the sample solution, amount of resin, eluent type, interfering ions and flow variables were studied. Under the optimum conditions, the calibration graph obtained was linear over the concentration range of 2–20 μg L−1. The detection limit of the method (3 σ) was 0.3 μg L−1 while precision was 1.5% (n=25) at the level of 10 μg L−1 Ag(I). The limit of quantification for the method, based on 20 σ, was 2.0 μg L−1. The enrichment factor was found to be 65 while the optimized sample volume was 13.6 mL. The accuracy of the method was performed by analyzing certified reference materials. The developed method was applied successfully for the determination of silver in different water samples with satisfactory results.

A method was developed for on-line solid phase preconcentration and cold vapour atomic absorption spectrometric determination of Cd(II) in aqueous samples. Lewatit Monoplus TP207 iminodiacetate chelating resin was used for the separation and preconcentration of Cd(II) ions at pH 4.0. The whole system was labmade. The influence of analytical parameters such as concentration of eluent and sodium tetrahydroborate solution, flow rate of eluent, sample, and Ar, and matrix ions were investigated. A preconcentration factor of 20 and a detection limit (3sb) of 2.1 ng L−1, along with a sampling frequency of 28 h−1 were achieved with 1.4 min of sample loading time and with 2.8 mL sample consumption. The relative standard deviation (R.S.D.) was 2.5% for 0.05 μg L−1 Cd(II) level. The developed method was used for Cd(II) analysis in water samples. The certified reference material (LGC6019) experimental results are in good agreement with the certified value.