Effects of neonicotinoid insecticide formulations and their components on Daphnia magna – the role of active ingredients and co-formulants

Formulating agents used in pesticide products have been regarded as inactive/inert components; however, several studies confirmed additive, synergistic or antagonistic effects between the active ingredients (AIs) and additives, or the individual toxicity of the formulating agents. The worldwide used neonicotinoid insecticides and their components can reach surface waters, due to their physico-chemical properties (e.g. water solubility) or improper application in chemical plant protection technology, and can adversely affect non-target aquatic organisms. Formulated pesticides were analysed for alkane sulphonate surfactants by using liquid chromatography coupled with tandem mass spectrometry. In acute immobilisation tests on Daphnia magna, differences were found among the toxicity of the investigated neonicotinoid AIs and formulations. The toxicity of a formulated insecticide (Apache 50 WG®– AI: clothianidin) was found to be 46.5 times more toxic than explained by its AI, probably due to toxic effect of the formulating agents on D. magna. In contrast, two preparations (Calypso 480SC® – AI: thiacloprid, Actara 240 SC®– AI: thiamethoxam) were 2–3 times less toxic than their AIs. Results indicate possible synergistic/antagonistic interaction with the AIs.     

超高效液相色谱-四极杆-飞行时间质谱法快速筛查农药制剂中非法添加的杀虫剂

建立了农药制剂中48种非法添加杀虫剂的超高效液相色谱-四极杆-飞行时间质谱（UPLC-Q-TOF MS）快速筛查方法。可湿性粉剂、乳油和悬浮剂3种剂型的农药制剂样品经甲醇溶解、提取后,采用UPLC-Q-TOF MS检测,48种杀虫剂在0.5～20 mg/L范围内线性关系良好,线性相关系数（R²）大于0.99。48种农药的定量限为0.05～0.4 mg/kg,检出限为0.01～0.2 mg/kg,低、中、高3个加标水平下的平均回收率为86.3%～101.5%,相对标准偏差为1.7%～4.0%。该方法快速、准确,可用于农药制剂中多种杀虫剂的快速筛查。     

Pesticides as Microemulsion Formulations

Conventional systems like wettable powders, emulsifiable concentrates (ECs), oil in water emulsions (O/W emulsions), water in oil emulsions (W/O emulsions), aqueous suspension concentrates etc. are popularly used as the pesticide formulations. However, the microemulsion systems are preferred for their long-term thermodynamic stability, low viscosity, cost economy, and aesthetic appeal. Such systems provide a method for preparing an isotropic mixture of oil and water. Major advantage of microemulsion is in usage of the widely, easily available, environmentally friendly, and least expensive diluents, water. Formulation of pesticide microemulsion is a difficult task. The present investigation deals with the systematic study to arrive at the economical composition for microemulsion and solubilized systems. These compositions gave maximum stability with the optimum usage of surfactants. The microemulsion and solubilized systems when further diluted with water gave macroemulsion and microemulsion respectively, which were stable over an extended period of time.     

Analysis of alcohol ethoxylates and alkylamine ethoxylates in agricultural soils using pressurised liquid extraction and liquid chromatography–mass spectrometry

Nonionic surfactants e.g. alcohol ethoxylates (AEOs) and alkylamine ethoxylates (ANEOs) are commonly utilised as adjuvants in pesticide formulations to enhance their effectiveness. In this study, analytical methods for AEO and ANEO determination in soil samples using pressurised liquid extraction (PLE) were developed and used in connection with LC–MS. The recovery of the method, which was highly dependent on the soil properties, varied in the range 47–106% for AEO and 27–109% for ANEO. Detection limits (LOD) were 7–13 µg kg^–1 for AEO and 24–43 µg kg^–1 for ANEO. The developed method has been applied to determine AEOs and ANEOs in surface soil samples from fields sprayed with glyphosate herbicides. Tallowalkylamine ethoxylates (an ANEO) were detected in the soil before and after pesticide application, with increasing concentrations after treatment. The highest concentration in the soil samples was observed for the ANEO homologues with the longest ethoxy chains; in the clay soil the concentration decreased with the length of the ethoxy chain. ANEOs added to pesticide formulations as a technical mixture will, as demonstrated in this study, behave as individual homologues, which is reflected in their behaviour in the environment.Abbreviations AEO Alcohol ethoxylates - ANEO Alkylamine ethoxylates - APEO Alkylphenol ethoxylates - APCI Atmospheric pressure chemical ionisation - ASE Accelerated solvent extraction - CEC Cationic exchange capacity - LC–MS Liquid chromatography–mass spectrometry - LOD Limit of detection - MAE Microwave-assisted extraction - PLE Pressurised liquid extraction - SD Standard deviation - SIM Selected-ion monitoring - SPE Solid-phase extraction - TEA Triethylamine     

Simultaneous Determination of Dipyrone and Papaverine in Pharmaceutical Formulation using PLS Regression and UV Spectrophotometry

Abstract

A combination of sodium dipyrone and papaverine hydrochloride is used as an analgesic and antispasmodic drug. A simple and rapid procedure is proposed for simultaneous determination of these drugs in commercial formulations (Melpaz^®) based on partial least squares (PLS) regression and UV spectrophotometric measurements in the range of 218–300 nm. The calibration set was built with 25 solutions in concentrations ranging from 15.0–35.0 mg ml^?1 for dipyrone and from 0.5–1.5 mg ml^?1 for papaverine in methanol. The relative standard deviation (RSD) was 1.05% for dipyrone and 1.55% for papaverine in pharmaceutical formulations. The percent of relative recovery was 95.9% for dipyrone and 95.2% for papaverine. Figures of merit, such as accuracy, precision, sensitivity and adjust were also determined. The methodology was validated by using an independent method, based on high performance liquid chromatography (HPLC).     

The Petroleum Industry Surfactants Synthesized from Fish Oils

Biodegradable surfactants for the petroleum industry have been synthesized by the sulfurization of fish oils. A qualitative composition analysis of surfactants was conducted by FTIR spectroscopy that showed the presence of sulfonic acid groups in the samples. Previously, several samples of the technical fish oils (fish processing waste) have been studied with regard to their use for the synthesis of biodegradable surfactants. It has been shown by gas–liquid chromatography, FTIR spectroscopy, high-performance liquid chromatography, and mass spectrometry method that samples under study contain a large amount of saturated and nonsaturated fatty acids with hydrocarbon radicals comprising from 16 to 22 carbon atoms. The results reveal that the concentration of oleic acid approaches to 15 wt%. Fish oils with a high content of free fatty acids were used as the basis for the synthesis of technical, environmentally friendly surfactants that can be applied in the petroleum industry.     

Representative commodity for five brassica vegetables based on the determination and dissipation of six pesticide residues

A Quick, Easy, Cheap, Effective, Rugged and Safe method for determination of thiophanate-methyl, carbendazim, metalaxyl, fluazifop-P-butyl, chlorpyrifos and lambda-cyhalothrin in five brassica vegetables by high performance liquid chromatography-mass spectrometry/mass spectrometry and gas chromatography-electron capture detector has been developed. The average recoveries of six pesticides in five brassica vegetables were in the range of 77.4%–117.4% with relative standard deviation of 3.7–10.8%. Residues of thiophanate-methyl, carbendazim, metalaxyl, fluazifop-P-butyl, chlorpyrifos and lambda-cyhalothrin in five brassica vegetables were studied with the developed method for the classification of crop group and selection of representative commodity of five brassica vegetables. Totally 48 open field trials on five brassica vegetables were conducted at two locations in two different seasons. The residue dynamics and final residues of the six pesticides at three preharvest intervals in different vegetables were compared. All six pesticides had the longest half-lives in cabbage (2.1–3.5 days). Residues of carbendazim (sum of thiophanate-methyl and carbendazim), metalaxyl, chlorpyrifos and lambda-cyhalothrin had similar trend in different brassica vegetables. The maximal concentrations of these pesticide residues were found in kale (0.28–10.9 mg kg^?1). Fluazifop-P-butyl residues were at low levels in all five brassica vegetables (<0.01–0.03 mg kg^?1). Cabbage, red cabbage, Brussels sprouts and kohlrabi had no significant difference in all six pesticide residues and could be classified in a subgroup of Head Brassicas. Cabbage should be selected as the representative commodity. Considering the highest residues in kale and its different morphology, kale should not be classified into the subgroup of Head Brassicas.     

气相色谱-质谱联用法测定农药制剂中29种助剂

建立了气相色谱-质谱联用法（GC-MS）同时测定农药制剂中29种助剂的方法。农药制剂经甲醇稀释,取上清液过0.22 μm滤膜后检测分析。采用VF-1701MS毛细管柱（60 m×0.25 mm×0.25 μm）分离,选择离子监测模式下（SIM）测定,外标法定量。结果表明,29种农药助剂在6.2~400.0 mg/L范围内线性关系良好,相关系数（R²）均大于0.99,方法定量限为4.4~439.1 mg/kg,乳油型和可溶液剂型农药样品的平均加标回收率分别为82.0%~111.9%和82.6%~112.9%,相对标准偏差为0.4%~7.2%和0.3%~8.2%（RSD,n=6）。应用该方法对110份农药制剂样品进行检测,其中28份检出苯酚、N-甲基吡咯烷酮、二氯甲烷、正己烷等共11种农药助剂,含量范围为0.05%~15.65%。此方法操作简单,灵敏度高,准确性好,适用于农药制剂中29种助剂的同时检测。     

Online antioxidant activity and ultra-performance LC-electrospray ionisation-quadrupole time-of-fight mass spectrometry for chemical fingerprinting of Indian polyherbal formulations

A HPLC–DAD–DPPH method was developed for evaluating the 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging activity of ethylacetate extracts of different polyherbal formulations (draksarista, draksava, lohasava and arvindasava) by using RP-18e column. The ethylacetate extract from polyherbal, ‘draksarista’ exhibited maximum free radical scavenging activity (99.9 ± 0.38%) followed by draksava (99.8 ± 0.34%), lohasava (98.5 ± 0.30%) and arvindasava (42.3 ± 0.34%) at 100 μg mL^? 1. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionisation-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study chemical composition of the ethylacetate extracts of formulations. The characteristic electrospray mass ionisation reveals the dominance of polyphenols and their glycosides in the four polyherbal formulations.     

Ultra-Performance Liquid Chromatography with Electrospray Ionization Tandem Mass Spectrometry for the Determination of Ketoconazole in Anti-Dandruff Shampoo

A fast and highly sensitive method for the quantification of ketoconazole in antidandruff emulsion formulas was developed and validated. Sample preparation utilizing solid-phase extraction was a simple and reliable method for extracting both ketoconazole and its internal standard miconazole from the samples: 97 ± 3% for ketoconazole and 93 ± 4% for the internal standard. The separation by isocratic ultra-high performance liquid chromatography and multiple-stage mass spectrometry with a reversed-phase C₁₈ column was performed within 10 min. The method, which operated in a selective reaction monitoring mode specific to ketoconazole, was validated for quantitative use. The intra- and inter-day precision values were <5% and their accuracies ranged from 89.6 to 96.2%. The ketoconazole concentrations in two samples obtained by the established protocol were comparable to the concentrations indicated on the labels of the formulations. Thus, this paper describes the first use of ultra-high performance liquid chromatography and multiple-stage mass spectrometry for the determination of ketoconazole.     

A review of liquid chromatography in environmental pesticide analysis

Summary The use of liquid chromatography in environental pesticide analysis is reviewed. In addition to classical UV and electrochemical detectors, detection systems such as mass spectromytry and gas chromatographytype detectors are discussed. The applicability of supercritical fluid chromatography to pesticide analysis is also reviewed.Presented at the 18th International Symposium on Environmental Analytical Chemistry, Barcelona 5–8 September, 1988.     

Identification and Simultaneous Determination of Mangiferin,Neomangiferin, Timosaponin A-III,and Timosaponin C in Rhizoma Anemarrhenae by Rapid Resolution Liquid Chromatography Coupled with Triple Quadrupole Mass Spectrometry

A new and rapid method was developed for simultaneous determination of mangiferin, neomangiferin, timosaponin A-III, and C in Rhizoma Anemarrhenae using rapid resolution liquid chromatography coupled with triple quadrupole mass spectrometry. The analysis was performed on an Eclipse Plus C₁₈ column (I.D. 4.6 × 100 mm, 3.5 μm). Electrospray ionization–tandem interface in the negative mode was employed prior to mass spectrometric detection. Quantitation was based on multiple reaction monitoring (MRM) for determination. Limits of detection (LODs) ranged from 0.7 to 3 pg. The average recoveries ranged from 98.16 to 100.7% with RSDs ≤ 2.03%. The established method was validated, sensitive, and reliable.     

Direct Enantiomeric Separation of Chiral Pesticides by LC on Amylose Tris(3,5-dimethylphenylcarbamate) Stationary Phase under Reversed Phase Conditions

Amylose tris(3,5-dimethylphenylcarbamate) chiral stationary phase was used by liquid chromatography under reversed-phase conditions for the chiral separation of 20 pesticides, of which ten samples were separated directly under suitable conditions. The influence of mobile phase composition and column temperature from 0 to 40 °C on the separation was investigated. The mobile phases were methanol/water or acetonitrile/water at a flow rate of 0.5 mL min^?1 with UV detection at 230 nm. The two enantiomers of fenamiphos, terallethrin, fenoxaprop-ethyl, benalaxyl and lactofen could obtain base separation under optimized conditions, while the enantiomers of quizalofop-ethyl, metalaxyl, napropamide, fluroxypyr-meptyl and 2,4-D-ethylhexyl got partial separation. The retention factors (k) and selectivity factor (α) for the enantiomers of most investigated pesticides decreased with increasing the temperature. The lnα–1/T plots for enantiomers of chiral pesticides were linear at the range of 0–40 °C except for that of metalaxyl, fenoxaprop-ethyl and 2,4-D-ethylhexyl enantiomers in methanol/water. The thermodynamic parameters calculated based on linear Van’t Hoff plots showed the chiral separation was controlled by enthalpy. Better separation was not always at low temperature. The chiral recognition mechanisms were discussed. The elution orders of the eluting enantiomers were determined by a circular dichroism detector.     

Simultaneous Determination of Propranolol Hydrochloride and Sodium Benzoate in Oral Liquid Preparations by HPLC

A simple, selective and sensitive HPLC–UV method for quantification of propranolol hydrochloride and sodium benzoate in oral liquid preparations was developed and fully validated. Separation was performed by Supelco Discovery^® C18 (25 cm × 4.6 mm, particles 5 μm) column. UV/VIS absorbance detector was set at wavelength 230 nm. Column oven was conditioned to 25 °C. Mobile phase was prepared by dissolving 1.6 g of sodium dodecyl sulphate and 0.31 g of tetrabutylammonium dihydrogen phosphate in 450 mL of ultrapure water; 1 mL of sulphuric acid (95–97 %) and 550 mL of acetonitrile were added. Sodium hydroxide solution (2.1 M) was used for adjusting pH to value 3.3 (±0.05). Retention times of sodium benzoate, propranolol hydrochloride and butylparaben (internal standard) were 2.2, 3.3 and 4.1 min, respectively. Newly developed method is suitable for simultaneous determination of propranolol hydrochloride and sodium benzoate in oral liquid preparations which are used for therapy of haemangiomas in paediatric patients. Method has been applied for stability testing of extemporaneous paediatric oral formulations containing propranolol hydrochloride.

     

Determination of Pesticide Residues in Cereals by Liquid Chromatography and UV Detection

Abstract

A chromatographic method to determine pesticide residues in cereals by high-performance liquid chromatography (HPLC) and ultraviolet (UV) detection has been described. The study focused on the preliminary purification procedure because of the analytical problems associated with the presence in these food matrices of high-molecular-weight compounds, such as lipids, triglycerides, celluloses, and starch, which can interfere and reduce the chromatographic separation efficiency of the analytes. The method proposed is based on the extraction of pesticide residues from 5 g of sample extracted with the use of petroleum ether and on cleanup with a C18 cartridge. The pesticides were eluted with acetonitrile. The column packed with solid support was eluted with a suitable solvent, and only a portion of flow outlet side of the UV detector was collected. Using the information of standard UV trace, it was possible to establish an appropriate portion and to ensure the collection of all pesticides analyzed. The simple and rapid proposal method has shown good recovery (70–110%) for different spiked levels of samples (0.025–0.1 mg/Kg) and could be applied to other food matrices that containing high-molecular-weight compounds.     

Simultaneous Determination of Propranolol Hydrochloride and Sodium Benzoate in Oral Liquid Preparations by HPLC

A simple, selective and sensitive HPLC–UV method for quantification of propranolol hydrochloride and sodium benzoate in oral liquid preparations was developed and fully validated. Separation was performed by Supelco Discovery^® C18 (25 cm × 4.6 mm, particles 5 μm) column. UV/VIS absorbance detector was set at wavelength 230 nm. Column oven was conditioned to 25 °C. Mobile phase was prepared by dissolving 1.6 g of sodium dodecyl sulphate and 0.31 g of tetrabutylammonium dihydrogen phosphate in 450 mL of ultrapure water; 1 mL of sulphuric acid (95–97 %) and 550 mL of acetonitrile were added. Sodium hydroxide solution (2.1 M) was used for adjusting pH to value 3.3 (±0.05). Retention times of sodium benzoate, propranolol hydrochloride and butylparaben (internal standard) were 2.2, 3.3 and 4.1 min, respectively. Newly developed method is suitable for simultaneous determination of propranolol hydrochloride and sodium benzoate in oral liquid preparations which are used for therapy of haemangiomas in paediatric patients. Method has been applied for stability testing of extemporaneous paediatric oral formulations containing propranolol hydrochloride.     

Comparative Spectrophotometric,Spectrofluorometric, and High‐performance Liquid Chromatographic Study for the Quantitative Determination of the Binary Mixture Felodipine and Ramipril in Pharmaceutical Formulations

Abstract

Two‐component mixtures of felodipine (FLD) and ramipril (RMP) were assayed by derivative UV spectrophotometry, spectrofluorometry, and high performance liquid chromatography (HPLC). The spectrophotometric methods included a zero‐crossing first‐ and second‐order derivative procedure and a derivative compensation technique for the determination of binary mixtures with overlapping spectra. The spectrofluorometric method was based on first‐ and second‐order derivatives of the emission spectra (zero‐crossing point). Results from these methods were compared with those obtained by an exclusively developed isocratic reversed phase HPLC method. A reversed‐phase Adsorbosil DS analytical column, with methanol‐acetonitrile‐water (50∶30∶20, v/v) mobile phase at a flow rate of 1.5 ml/min, was used with a UV detector. The temperature was set at 25±0.2°C. Results obtained by the spectrophotometric and spectrofluorometric methods were comparable to those obtained by the HPLC method, as far as analysis of variance (ANOVA) test results were concerned. It is concluded that the developed methods are equally accurate, sensitive, and precise; with direct and simple application to pharmaceutical formulations of felodipine and ramipril combination, without interference from common pharmaceutical adjuvants.     

Gas chromatographic determination of bifenthrin in technical and selected formulated products: collaborative study

A GC method for the analysis of technical and formulated bifenthrin samples was evaluated in a collaborative study. Bifenthrin is determined by using a 50% (trifluoropropyl)-methylpolysiloxane wide-bore capillary column and flame ionization detector. Ten samples, consisting of four formulations and a technical material were analyzed by 12 collaborators using Youden pairs. The four formulation types included in this study were microemulsion (ME), wettable powder (WP), suspension concentrate (SC), and emulsifiable concentrate (EC). Variability in the analysis of two of the formulation types, SC and EC, was later found to be due to the noncommercial containers used to hold the test samples. Because of this, valid data could not be obtained for the EC and SC. For the two formulations for which valid data could be obtained, ME and WP, and the technical chemical, accuracy and variability results are typical of large data sets. For the technical chemical and the two formulations for which valid data were obtained, Official First Action is recommended.     

RP–LC Simultaneous Determination of Aconitine, Solanine and Piperine in an Ayurvedic Medicine

By optimizing the extraction, separation and analytical conditions, a reliable, rapid, simple and accurate liquid chromatography method with UV detection was developed for the simultaneous quantitative determination of aconitine, solanine and piperine in an ayurvedic preparation prepared from Aconitum ferox, Solanum indicum, Piper nigrum and Piper longum. The separation of these alkaloids was achieved on an reversed phase C-18 column (250 mm × 4.6 mm ID, 5 μm particle size), with isocratic elution using a mixture of acetonitrile–potassium hydrogen phosphate buffer (10 mM, pH 7.5)–methanol (60:25:15, v/v) at a flow rate of 1 mL min^?1 with UV detection at 227 nm for aconitine and solanine while 343 nm for piperine. The calibration curves were linear with correlation coefficients of 0.9990, 0.9942, 0.9989 for solanine, piperine and aconitine, respectively. The % Relative standard deviation (%RSD) values were less than 2% in the concentration range of 10–100 μg mL^?1 for all the three alkaloids. Intra-day assay and inter-day assay precision of the analytes were less than 2%, and the average recovery rates obtained were in the range of 98–102% for all with %RSD below 2%. Quantitative analysis of the alkaloids in the laboratory and marketed formulations showed that the contents of the alkaloids varied significantly. This method can provide a scientific and technical platform to the product manufacturers for setting up a quality control standard as well as to the public for quality and safety assurance of the proprietary ayurvedic formulations.     

液相色谱在食物和中药中的农药残留分析中的应用

综述了近年来液相色谱分析方法在食物和中药中农药残留分析中的应用,对各种常用的在线和离线样品预浓缩技术、检测器以及液相色谱与质谱等仪器的联用进行了讨论,并对液相色谱在农药残留分析中的应用前景进行了评价。