Comparison of Microwave Assisted Extraction with Conventional (Homogenization,Vortexing) for the Determination of Incurred Salinomycin in Chicken Eggs and Tissues

Abstract

Incurred and fortified salinomycin residues were extracted from chicken tissues and eggs by homogenization, vortexing and by microwave assisted extraction. The salinomycin residues were quantitated by liquid chromatography following postcolumn derivatization with either vanillin or 4-dimethylamino-benzaldehyde and detected at 520 or 592 nm, respectively. Comparison of residue data indicated that microwave assisted extraction performed as well as the vortexing technique in extracting salinomycin residues in the tissues of laying chickens that were fed meal containing drugs at various level. In the present study, extracts from homogenizing could not be analyzed directly without clean up. Therefore, microwave assisted extraction appears to be a reliable, reproducible, and economical substitute for routinely used homogenization and vortexing extraction techniques.     

Microwave extraction of incurred salinomycin from chicken tissues

Abstract

A rapid, accurate, environmentally friendly and cost‐effective microwave extraction technique was developed for the extraction of spiked and incurred salmomycin from chicken tissues (kidney, liver, muscle, ovarian yolk and fat). Extraction of salinomycin from various tissues was achieved by irradiating the sample in absolute ethanol and 2‐propanol (15+2) for 9 sec. in a common household microwave oven. The extract was analysed without further cleanup by HPLC on a C₁₈ column (5 μm) and detected at 592 nm via post‐column reaction with 4‐dimethylaminobenzaldehyde (DMABA) in a heated reactor coil at 86° C. Recoveries of salinomycin from spiked tissues at 30 ng/g level ranged between 87 and 100%. The limit of quantitation was found to be 10 ng/g. The developed method was applied for the analysis of incurred tissues and ovarian yolk of laying chickens given sodium salinomycin in feed at different levels for 14 consecutive days followed by withdrawal periods. Residues were detected in all tissues and ovarian yolk at 0 withdrawal time but declined during the withdrawal period. Highest residue were found in fat and ovarian yolk.     

Optimized microwave extraction for trace detection of 2,4,6-trinitrotoluene in soil samples

An optimized microwave assisted extraction method for determination of trinitrotoluene (TNT) and related compounds in soil is presented. The new enhanced method exhibits improved extraction recovery and precision as well as sample handling time. For the separation and detection gas chromatography coupled to a thermoionic probe was used achieving TNT and dinitrotoluene detection limits per injection at the femtogram level. The generated extraction recovery and precision data are given for spiked and certified soil. Determined TNT and related compounds residues in soil collected from different parts of the world are presented.     

Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil

A superficial water quality survey in a watershed of the Paraíba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresópolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments.     

Evaluation of pressurized liquid extraction for the analysis of four pesticides in unpolished rice

The aim of to evaluate efficiency of this study was extraction pressurized liquid extraction (PLE) for the analysis of four pesticides, fthalide, etofenprox, fenitrothion, and isoprothiolane, in unpolished rice by comparing with homogenization as a reference technique. The concentrations of four selected pesticides obtained by PLE with acetonitrile at 130°C for 10 min × 2 cycles were comparable to those by homogenization with water-soaking. The repeatability of the analysis, represented as relative standard deviations (RSDs), were 1.4–3.6% (n = 3) for PLE at 130°C and 1.2–3.8% (n = 3) for homogenization with water-soaking. Recovery yields of surrogates were 75–88% and 87–109% for PLE at 130°C and homogenization with water-soaking, respectively, and these were satisfactory according to the method of positive list. This study suggested that PLE can be applied for the analysis of selected four pesticides in unpolished rice as well as homogenization with water-soaking.     

Evaluation of pressurized liquid extraction for the analysis of four pesticides in unpolished rice

The aim of to evaluate efficiency of this study was extraction pressurized liquid extraction (PLE) for the analysis of four pesticides, fthalide, etofenprox, fenitrothion, and isoprothiolane, in unpolished rice by comparing with homogenization as a reference technique. The concentrations of four selected pesticides obtained by PLE with acetonitrile at 130 degrees C for 10 min x 2 cycles were comparable to those by homogenization with water-soaking. The repeatability of the analysis, represented as relative standard deviations (RSDs), were 1.4-3.6% (n = 3) for PLE at 130 degrees C and 1.2-3.8% (n = 3) for homogenization with water-soaking. Recovery yields of surrogates were 75-88% and 87-109% for PLE at 130 degrees C and homogenization with water-soaking, respectively, and these were satisfactory according to the method of positive list. This study suggested that PLE can be applied for the analysis of selected four pesticides in unpolished rice as well as homogenization with water-soaking.     

土壤中多氯联苯分析方法研究进展

文中综述了多氯联苯的分析技术及其研究进展。介绍了样品前处理技术如索氏萃取法、超声萃取法、微波辅助萃取、超临界流体萃取、加速溶剂萃取等在土壤样品中多氯联苯分析中的应用;阐述了气相色谱、液相色谱、气质联用技术在土壤样品中多氯联苯的检测,并对土壤中未来多氯联苯检测技术的发展提出了展望。     

砷形态分析中的样品前处理方法

本文对近 10多年来砷形态分析中样品的前处理技术及其在不同样品中的应用进行了总结和评述 ,指出 ,断续低功率微波辅助提取、经典索氏萃取和纯乙醇低温冷冻离心提纯这 3种砷化物前处理技术较其他方法更具优势     

微波提取酱渣中总异黄酮的实验研究

采用微波法提取酱油废渣中的总异黄酮,并对酱渣异黄酮提取实验中的微波功率、乙醇浓度、料液比、微波作用时间及提取次数等影响因素进行探讨。在单因素试验的基础上,用正交实验进行酱渣总异黄酮提取工艺参数的优化。正交实验结果表明,微波法提取总异黄酮的最佳工艺条件为:微波功率560 W,乙醇浓度80%,料液比1∶20,微波间歇提取3 m in,在此条件下酱渣总异黄酮浸出率达到90%以上。与传统的热浸提法相比,微波提取法具有提取率高,提取速度快,选择性好及能耗小等特点。     

Determination of veterinary pharmaceuticals in poultry litter and soil by methanol extraction and liquid chromatography-tandem mass spectrometry

Pharmaceuticals are emerging contaminants with potential risks to the environment and human health. A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed for determination of the antimicrobials virginiamycin, monensin, salinomycin, narasin and nicarbazin in poultry litter and soil. This method involves methanol extraction and clean-up of extracts through glass microfibre filters, introduction of the extracts and separation of compounds on a Zorbax Eclipse XDB C8 column, and compound detection in a Quattro Micro Micromass spectrometer. For litter samples, Method Detection Limits ranged from 0.1–0.6 μg Kg^{? 1}, while Limits of Quantitation (LOQs) were 2, 1, 0.4, 1 and 2 μg Kg^{? 1} for virginiamycin, monensin, salinomycin, narasin and nicarbazin, respectively. For soil samples calculated LOQs were 2, 3, 1, 1, and 1 μg Kg^{? 1} for virginiamycin, monensin, salinomycin, narasin and nicarbazin, respectively. Application of the LC-MS-MS method for detection of veterinary pharmaceuticals in litter collected from commercial poultry farms showed that compounds were present at concentrations ranging from 10–11,000 μg Kg^{? 1}.     

Extraction of organic contaminants from marine sediments and tissues using microwave energy.

In this study, we compared microwave solvent extraction (MSE) to conventional methods for extracting organic contaminants from marine sediments and tissues with high and varying moisture content. The organic contaminants measured were polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and polycyclic aromatic hydrocarbons (PAHs). Initial experiments were conducted on dry standard reference materials (SRMs) and field collected marine sediments. Moisture content in samples greatly influenced the recovery of the analytes of interest. When wet sediments were included in a sample batch, low recoveries were often encountered in other samples in the batch, including the dry SRM. Experiments were conducted to test the effect of standardizing the moisture content in all samples in a batch prior to extraction. SRM1941a (marine sediment). SRM1974a (mussel tissue), as well as QA96SED6 (marine sediment), and QA96TIS7 (marine tissue), both from 1996 NIST Intercalibration Exercise were extracted using microwave and conventional methods. Moisture levels were adjusted in SRMs to match those of marine sediment and tissue samples before microwave extraction. The results demonstrated that it is crucial to standardize the moisture content in all samples, including dry reference material to ensure good recovery of organic contaminants. MSE yielded equivalent or superior recoveries compared to conventional methods for the majority of the compounds evaluated. The advantages of MSE over conventional methods are reduced solvent usage, higher sample throughput and the elimination of halogenated solvent usage.     

微波辅助工艺处理天然气净化废水的应用研究

进行了微波辅助工艺处理天然气净化废水的应用研究,考察了废水色度、COD、SS、含油量和细菌的去除效果以及对废水腐蚀率的降低作用,并进行了同等条件下的常温对照实验。研究结果表明:微波絮凝工艺中絮凝剂PAC和PAM的用量较常温下减少了100 mg/L和5 mg/L,絮凝沉降时间仅为常温絮凝的1/4,最佳微波辐照时间下废水的COD去除率比常温条件下提高4.6%。微波工艺处理后,难降解天然气净化废水的含油量去除率达到了94%、废水中硫酸盐还原菌死亡率达97%以上,废水腐蚀率降为原来的1/7,废水可生化性得到了很大提高,可直接进行好氧生化处理。实验表明,微波辅助工艺对难降解天然气净化废水具有很好的处理应用效果。     

微波辅助-活性炭法处理电厂EDTA锅炉清洗废水可行性研究

采用微波辅助-活性炭法处理电厂EDTA锅炉清洗废水,研究了微波辐射时间、微波功率以及再生次数对活性炭吸附能力的影响,并根据实验结果设计了工艺流程,分析了微波辅助-活性炭法处理电厂EDTA锅炉清洗废水的可行性.研究表明,微波辅助-活性炭法处理EDTA清洗废水的最佳微波辐射时间和微波功率分别为5 min和680 W,微波辐...     

微波辅助疏水膜的清洗

针对膜蒸馏过程中膜表面常见的CaSO4垢和腐殖酸混合垢,对微波强化疏水膜清洗的效果进行了研究。结果表明,对于膜表面的CaSO4垢,微波辅助清洗效率高于常规清洗,且在清洗液的温度和流速较低时,微波的强化清洗效果更为明显;对于膜表面的腐殖酸混合垢,微波辅助清洗后的初始通量恢复率为88.4%,比常规清洗高出10.8%,同时可以相对缓解疏水膜的亲水化。     

The efficiency of two standardized procedures for extracting mutagenic chemicals from soils

A major technical limitation to monitoring the fate of mutagenic compounds in soil is the lack of an established extraction procedure. This study was conducted to evaluate the efficiency of the blender extraction procedure for extracting benzo(a)pyrene (BAP) or 2-nitrofluorene (2NF) from a Weswood silt loam or a Bastrop clay loam soil. Extracted residues were evaluated using the Salmonella/microsome mutagenicity assay and high performance liquid chromatography (HPLC) to quantify recovery of the two chemicals from soil. In addition, a limited study using only the mutagenicity assay was conducted to compare the efficiency of the Blender and Soxhlet extraction procedures for recovering organic mutagens from both soils amended with a wood preserving bottom sediment waste.Extracted residues were dissolved in dimethylsulfoxide to concentrations that could be detected in the bioassay. Over all treatment levels and for both soils, the extraction efficiency of the blender procedure for BAP was greater than 80% for 12 of 16 treatments as measured using both bioassay and HPLC analysis; while, for 2NF the extraction efficiency was greater than 90% for all 15 treatments as measured by HPLC, and greater than 80% for twelve of 15 treatments as measured by bioassay. These results indicate that blender extraction provided efficient recovery of the pure compounds tested. When the efficiency of the blender and Soxhlet procedure for extracting the wood-preserving bottom sediment and waste amended soil were compared, significantly greater levels of mutagenic activity were detected in the fractions extracted using the blender extraction than were detected using the Soxhlet extraction.     

Evaluation of pressurized liquid extraction for determination of organophosphorus and pyrethroid pesticides in soybean

The purpose of this study was to develop an analytical method for the determination of organophosphorus and pyrethroid pesticides in soybean by pressurized liquid extraction (PLE). Two organic solvents, acetone and acetonitrile, were evaluated as extraction solvents. In both cases, the amount of extract was enhanced with increasing extraction temperature. The extracts obtained using acetonitrile were measured by gas chromatography/mass spectrometry after a cleanup process based on the analytical method for the Japanese Positive List System for Agricultural Chemicals Remaining in Foods. The effect of extraction temperature (range: 40– 130°C) on extraction efficiency was evaluated by a recovery study using 21 organophosphorus pesticides and 10 pyrethroid pesticides as target analytes and acetonitrile as the solvent. The results indicated that at 130°C, some organophosphorus pesticides might be degraded, whereas extraction temperatures between 70°C and 100°C were optimal. Next, a prepared sample containing fenitrothion and permethrin was analyzed. Although the sample was not soaked in water prior to analysis, PLE provided analytical results comparable to those obtained by solvent extraction with homogenization. Therefore, PLE is considered a simple and alternative technique for the extraction of organophosphorus and pyrethroid pesticides in soybean.     

Evaluation of pressurized liquid extraction for determination of organophosphorus and pyrethroid pesticides in soybean

The purpose of this study was to develop an analytical method for the determination of organophosphorus and pyrethroid pesticides in soybean by pressurized liquid extraction (PLE). Two organic solvents, acetone and acetonitrile, were evaluated as extraction solvents. In both cases, the amount of extract was enhanced with increasing extraction temperature. The extracts obtained using acetonitrile were measured by gas chromatography/mass spectrometry after a cleanup process based on the analytical method for the Japanese Positive List System for Agricultural Chemicals Remaining in Foods. The effect of extraction temperature (range: 40- 130°C) on extraction efficiency was evaluated by a recovery study using 21 organophosphorus pesticides and 10 pyrethroid pesticides as target analytes and acetonitrile as the solvent. The results indicated that at 130°C, some organophosphorus pesticides might be degraded, whereas extraction temperatures between 70°C and 100°C were optimal. Next, a prepared sample containing fenitrothion and permethrin was analyzed. Although the sample was not soaked in water prior to analysis, PLE provided analytical results comparable to those obtained by solvent extraction with homogenization. Therefore, PLE is considered a simple and alternative technique for the extraction of organophosphorus and pyrethroid pesticides in soybean.     

Testing the efficiency of extraction of incurred residues from soil with optimized multi-residue method

The reproducibility of extraction of residues from spiked soil samples and from soils containing incurred residues was tested with ¹⁴C-labeled test compounds of different physical-chemical properties. Nearly 100% of the compounds added to the sample before extraction could be recovered with an average reproducibility relative standard deviation (CV) of 5.4%. The additional steps of the determination process (cleanup, evaporation, etc.) contributed to the major part of the variability of the results (CV = 10–20%). The incurred residues were most efficiently extracted with acetone for 30 min followed by the mixture of acetone/ethyl acetate 1:1 for additional 30 min. However, they could only be recovered at various extent (64–90% of total residues), underlying the importance of testing the efficiency of extraction. The residues were identified and quantified by gas chromatography applying thermionic detector. The performance parameters of the method complied with the international method validation guidelines, and they proved to be robust and suitable for determination of pesticide residues in soils of widely different physical–chemical properties.     

Fatty acid profile and elemental content of avocado (Persea americana Mill.) oil--effect of extraction methods

Interest in vegetable oil extracted from idioblast cells of avocado fruit is growing. In this study, five extraction methods to produce avocado oil have been compared: traditional solvent extraction using a Soxhlet or ultrasound, Soxhlet extraction combined with microwave or ultra-turrax treatment and supercritical fluid extraction (SFE). Traditional Soxhlet extraction produced the most reproducible results, 64.76 ± 0.24 g oil/100 g dry weight (DW) and 63.67 ± 0.20 g oil/100 g DW for Hass and Fuerte varieties, respectively. Microwave extraction gave the highest yield of oil (69.94%) from the Hass variety. Oils from microwave extraction had the highest fatty acid content; oils from SFE had wider range of fatty acids. Oils from Fuerte variety had a higher monounsaturated: saturated FA ratio (3.45-3.70). SFE and microwave extraction produced the best quality oil, better than traditional Soxhlet extraction, with the least amount of oxidizing metals present.     

Persistence of antibiotics such as macrolides, tiamulin and salinomycin in soil

The extensive use of veterinary drugs in agriculture leads to contamination of manure. If this manure is used as fertiliser, soil may be exposed to the respective drugs. Additionally soil exposure may stem from contaminated sewage sludge that is used on some agricultural land as fertiliser. This study focuses on the fate of antibiotics in soil. We present a 120-day degradation experiment of six commonly used antibiotics: erythromycin, roxithromycin oleandomycin, tylosin, salinomycin and tiamulin in soil as well as calculating the resulting half-lives. The half-lives were 20 days for erythromycin, 27 days for oleandomycin, 8 days for tylosin, 16 days for tiamulin and 5 days for salinomycin; all according to 1st order kinetics. The concentration of roxithromycin remained nearly unchanged during the whole experiment.