Solvent Extraction Of Samples Research Articles

A high-throughput UPLC-MS-MS Bio-analytical method for the analysis of veterinary pharmaceutical residues in Chicken Tissues, Application of efficient-valid-green (EVG) Framework as a Competence Tool

Antibacterial medications are receiving the most attention due to hypersensitivity reactions and the emergence of bacterial mutants resistant to antibiotics. Treating Animals with uncontrolled amounts of antibiotics will extend beyond their lives and affect humans. This study aims to determine the concentration of the residues of sulfadimidine, sulfaquinoxaline, diaveridine, and vitamin K3 in the tissues of poultry (muscles and liver) after treatment with the combined veterinary formulation. A UPLC-MS-MS method was developed using Poroshell 120 ECC18 and a mobile phase composed of acetonitrile and distilled water, containing 0.1 % formic acid, in the ratio of (85:15 v/v) at a flow rate of 0.6 mL/min. Sample extraction solvent was optimized using response surface methodology (RSM) to be acetonitrile: methanol in the ratio (49.8: 50.2 v/v), and the method was validated according to the FDA bioanalytical method validation protocol over the range (50–1000 µg/Kg) for sulfaquinoxaline and (50–750 µg/Kg) for the other 3 drugs. The greenness of the sample preparation and analytical method was assessed by applying Analytical Eco-scale (AES) and AGREE coupled with AGREEprep. The Competence of the study was evaluated via the EVG framework known as Efficiency, validation, and greenness, to achieve a balance point represented by a radar chart. The method was applied to decide the time required for poultry products to be safe for human use after administration of the studied drugs. It was found that, after the administration of the last dose, minimally 7 days are required till the levels of the drugs drop to the maximum residue limit determined by the FDA/WHO in animal tissues.

Developing a comprehensive analytical protocol for forensic sexual lubricant analysis – Part 1: Implementing a sexual lubricant database for forensic casework

The increased use of condoms may be one reason why there is a reduced potential of finding DNA evidence in sexual assault cases. This dilemma has led to research in other trace evidence, such as sexual lubricants. In the absence of DNA, the analysis of trace lubricant residue may aid in connecting the suspect to the victim and/or crime scene. In this study, 162 samples from different lubricant manufacturing types were analyzed and classified based on the components identified in the sample. This study developed FTIR, GC–MS, and DART-HRMS methods and protocols that can be used to analyze samples and identify lubricant components for forensic purposes. Neat and solvent extracts of samples were analyzed in triplicate via the DART-HRMS and FTIR; however, only the extracts were analyzed by GC–MS in triplicate. Multivariate statistical techniques included hierarchical cluster analysis, principal component analysis, linear discriminant analysis, Fisher's ratio, and least absolute shrinkage and selection operator (LASSO) regression were used to characterize the lubricants to develop a comprehensive classification scheme for the lubricants. The classification scheme was tested using an internal dataset and an external independent test set to evaluate the accuracy of the developed model(s) for unknown samples. The classification scheme developed from this study and provided along with the database will allow analysts to classify unknown lubricants and lubricant residues found at crime scenes using analytical results from the aforementioned instruments. This research will aid in classifying unknown sexual lubricants based on components indicative of a particular class.

Rapid, simple and green solid phase extraction based on polyaniline nanofibers-mat for detecting non-steroidal anti-inflammatory drug residues in animal-origin food

In this study, polyaniline modified polyacrylonitrile nanofibers mat (PANI NFsM) was prepared as a novel adsorbent for the solid-phase extraction (SPE) of non-steroidal anti-inflammatory drug residues in meat or egg samples. The solvent extracts of samples were simply diluted with water to perform the SPE, and then the eluent was directly analyzed. Significant reduction of the matrix effect was obtained after SPE using only 5 mg of PANI NFsM. The entire sample preparation time is 5–10 times lower than the existing methods. The limits of detection of the target analytes ranging from 0.6 to 12.2 µg kg−1 had already met the demand of food safety monitoring by only 1 g sample. The recoveries ranged from 85.18% to 107.31%, with the intra-day and inter-day relative standard deviations of 2.74% to 16.01%, revealing satisfactory accuracy and precision. Finally, real samples analyses were applied to verify the practicability of the method.

A method for determining pyrene in mucus using synchronous fluorimetry with multiple standard additions

A new method was proposed to determine pyrene in mucus, which combined the synchronous fluorimetry with the multiple standard addition method (SFMSA). The method was used to determine pyrene in mucus directly without pretreatment. The method detection limit (MDL) for pyrene in mucus was measured as 0.47 ng/ml with a relative standard deviation of 12.7% ( n = 7). The standard addition graph was linear in the range 0.05–50.00 ng/ml ( r 2 = 0.9989). SFMSA was validated using a GC/MS method as a reference method, and nice agreement was found. The pyrene in mucus can be directly monitored by SFMSA without solvent extraction of samples. This indicates that SFMSA is more timesaving, less laborious and cheaper than the GC/MS method with solvent extraction. SFMSA has lower MDL and higher average recovery than the GC/MS method.

HPLC determination of salinomycin and related compounds in fermentation media of Streptomyces albus and premixes

A rapid, sensitive and selective HPLC method with post-column derivatization was proposed for the determination of salinomycin and related products in fermentation broths and premixes. The solvent extracts of samples were analysed on a reversed-phase monolithic type column. The mobile phase consisted of methanol/zinc acetate (0.05 M) adjusted to pH 4.0 with acetic acid (85/15, v/v). Post-column derivatization with vanillin at 85 °C was used for simultaneous, selective detection of salinomycin at 520 nm and related products at 460 nm. Optimal ratio of mobile phase/reagent flow rate was 2:1. Alternatively, pre-column derivatization of salinomycin and related products with three different reagents (2,4-dinitrophenylhydrazine, p-bromophenacyl bromide and p-nitrobenzoyl chloride) was examined. Suitable derivates for HPLC separation and UV detection were prepared using p-nitrobenzoyl chloride. Extraction ability of various solvents for extracting of salinomycin and co-products from premix samples was also tested. Acetone, ethanol and pyridine were found to be the best extraction solvents for these compounds.

A study of different soots using pyrolysis–GC–MS and comparison with solvent extractable material

This paper presents characterisation data for a range of soots produced by combustion from ethylene, benzene and kerosene, and soot from the biomass materials willow coppice and oat straw. Soot samples from laminar flames burning the hydrocarbons have been characterised using heated probe mass spectrometry (MS) and gas chromatography (GC)–MS. In some cases fractional pyrolysis–GC–MS was performed at 400 °C/1000 °C. Solvent extraction of samples in toluene or methanol was also employed. Three main categories of material are found for each soot sample: loosely bound solvent extractable material, more strongly bound higher molecular weight material that is difficult to resolve, and highly developed soot. Biomass soot also shows this three component composition although a much wider range of polycyclic aromatic and of oxygenated compounds are present.

Novel method for determining pyrene biodegradation using synchronous fluorimetry

To study the biodegradation rate of pyrene dissolved in liquid medium supplemented with mineral salts, a synchronous fluorimetry (SF) method was established. The limit of detection for pyrene dissolved in mineral salts medium (MSM) was determined as 0.19 ng/ml with a relative standard deviation of less than 1.3% ( n=9). The pyrene degrading rates of four bacterial strains were investigated using this method under the same experimental conditions. The degradation rates of the three active strains ranged from 76% to 87% after a 14-h incubation. The results were confirmed by the gas chromatography with a flame ionized detector (GC/FID) method. This implies that pyrene degradation can be directly monitored by the SF method without the solvent extraction of samples. The advantages of SF are that it is less laborious, faster, and less expensive than the GC/FID determination method with solvent extraction. The SF method provides a new tool for studying the degradation of polynuclear aromatic hydrocarbons (PAHs) in the natural environment and under experimental conditions.

Identification of Petroleum in Estuarine Waters

A simple sequential scheme of analysis suitable for the unequivocal demonstration of petroleum products present as pollutants in the estuarine environment is described. This scheme involves the use of gas chromatographic analysis of head space vapor and solvent extraction of samples followed by infrared spectrophotometric and paper chromatographic examinations.