Static headspace combined with GAS chromatography/mass SPECTROMETRY is a powerful technique which can be used for separation and identification of volatile organic compounds in complex and different matrices such as soil, water, blood, urine, milk, cheese and especially yogurt. After sample collection, they were analyzed by HS-GC/MS system and the components (acetaldehyde, acetone, butanone and acetic acid) were detected and quantified. The limit of detection (LOD) was 100 ng/kg with selected ion monitoring (SIM) mode at m/z =60 for acetic acid. The relative standard deviation (RSD) was measured at 5.5% for acetic acid.

Background: Epilepsy is one of the most common neurological conditions and a significant cause of morbidity and mortality. Objectives: The present study aimed to evaluate the anticonvulsant activity of the petroleum ether extract of the root of Anacyclus pyrethrum on Pentylenetetrazole (PTZ)-induced seizure model in Wistar rats. Methods: The composition of the petroleum ether extract of A. pyrethrum was first analyzed using GAS CHROMATOGRAPHY-MASS SPECTROMETRY (GC-MS). Subsequently, the anticonvulsant activities of these extracts (70 and 140 mg/kg, intraperitoneal injection) were evaluated on PTZ-induced seizures in rats. The protection rate against induced seizures, latency, and duration of seizures, as well as neurological symptoms, were assessed and compared to those protected by phenobarbital. Results: GC/MS analysis of the petroleum ether extract showed that the main components were octadecadienoic acid, hexadecanoic acid, diheptylcyclopropene, naphthalene, and methyl stearate. The extract (70 and 140 mg/kg) was found to provide significant protection against PTZ-induced seizures. Moreover, compared to the negative control, the extracts increased the latency of induced-convulsion and reduced the duration of epilepsy. Interestingly, the extracts showed a reduction in neurological symptoms and the severity of seizures compared to the negative control. All of these outcomes manifested in a dose-dependent manner. Conclusion: The petroleum ether extract of A. pyrethrum may produce anticonvulsant effects by reducing the duration of seizures and delaying the latency of seizures induced by PTZ.

Water contamination due to the wide variety of pesticides used in agriculture is a global environmental pollution problem. In order to reach at sub-mgL-1 levels of detection, an efficient extraction technique is required. A simple, fast and economical method, dispersive liquid-liquid micro extraction (DLLME), followed by GAS CHROMATOGRAPHY-MASS SPECTROMETRY was assessed for determining endosulfan in water samples. Experimental parameters which control the performance of DLLME, such as extraction and disperser solvents type and their volumes, temperature, and salt addition were studied by experimental design. The main factors affecting the extraction efficiency, volumes of disperser and extraction solvents, were optimized by response surface method. Under optimum conditions, the method was linear over the range 0.1-50 mg/L. The enrichment factor and extraction recovery were 163.4 and 63.73, respectively. Correlation coefficient and limit of detection (LODs) are 0.9996, 20 ng/L, respectively.

Objective: It has been greatly attempted to learn more about chemical information on finger prints using new vehicular technique use for the detection of a variety of substances, including narcotic drugs and medicines, as well using nano particles bound to specific antibodies. Over the last few years, the sensitive techniques of GAS chromatography and mass SPECTROMETRY have been found for the detection of residues in samples with very low values. Method: In this study, sampling from fingerprints was taken through optimized methods with chemical solvents and then by the techniques of GAS chromatography/mass SPECTROMETRY (GC/MS) for the detection of chemicals in the fingerprints. Samples included a group of volunteers aged 30 to 40 years. Sampling was done by means of glass slides and extraction with solvents of sodium hydroxide, methanol, and chloroform solutions. Analysis and detection of debris, including nicotine, Tramadol, Methamphetamine, and Cocaine was fulfilled using derivatization and GAS chromatography/mass SPECTROMETRY. Findings: The results showed that the use of derivatization as a sensitive method along with GAS chromatography/mass SPECTROMETRY can detect very small amounts of nicotine in existing samples. Conclusion: The results of this research can be used as a way to detect drug residues in finger prints and ultimately they can be important in providing a standard method for the analysis of these residues.

Background: Oxytetracycline (OTC) is a widely-used antibiotic; metabolism studies indicate only partial assimilation of it inside the body. Traditional wastewater treatment plants cannot remove OTC, and this results in the release of considerable amounts of the drug into aquatic environments. There is much concern over the role of residual antibiotics in the development of new generations of bacteria with modified resistance to the antibiotics. The present work investigated the possibility of OTC sorption on river sediments. Methods: Seven sediment samples were collected from various locations and depths of the Passaic River in New Jersey. The texture, clay, extractable iron, and organic matter contents of the sediments were determined. Pyrolysis-GAS CHROMATOGRAPHY-MASS spectrometric (Py GC-MS) analysis indicated the presence of 3 categories of organic materials: petroleum hydrocarbons, anthropogenic, and plant residual materials. The sediment samples were equilibrated with OTC solutions for 24 hours followed by centrifugation and syringe filtration. The residual OTC contents were determined by high performance liquid chromatography. Results: It appeared that 35%-60% fractions of OTC were retained by the sediments. The sorption capacity values of the sediments were correlated with clay content, organic matter content, and available iron. A poor correlation was found between adsorption capacity and clay content in the presence of organic matter and iron. Meanwhile, a relatively strong correlation was found between adsorption capacity with the iron, R2 = 0. 7499, and organic matter contents of the sediments, R2 = 0. 7899. Thus, the sorption of OTC on sediments is governed by all constituents. Conclusion: It was concluded that the antibiotic-sediment interaction is controlled mainly by the organic matter and iron contents.

Background and Purpose: The application of natural smoke, particularly in traditional medicine, is prevalent in over 50 countries for therapeutic reasons, however, the chemical compositions and biological characteristics of many of these smokes remain inadequately identified. A notable instance is the medicinal smoke of Anbarnesa (the dung of the domesticated species Equus asinus), which has been traditionally employed to address various diseases. This study aimed to determine the chemical compositions of Anbarnesa smoke from both male and female donkeys and to explore its antioxidant capacity through GC/MS analysis. Materials and Methods: Dung from both male and female donkeys (including immature and lactating ones) was gathered in the spring from the Meshginshahr region of Ardabil province. The smoke produced from their combustion was captured and concentrated in methanol. Following the extraction process, the samples were prepared for chromatographic analysis. Results: A total of 53 compounds were detected across six distinct samples, all with identification percentages exceeding 90%. Among the primary components were phenolic compounds, including phenol, guaiacol, p-cresol, and o-cresol. The total phenol percentage in the samples ranged from 37% to 60%. Conclusion: Based on the results of this study, Anbarnesa smoke contains a substantial amount of phenolic compounds and exhibits considerable antioxidant properties, which may serve as a foundation for its therapeutic applications and additional studies.

Centella asiaticais a herbaceous plant and known as pegaga in Malaysia. It was commonly used as a healing agent and constituent to improve mental ability because contains polyphenols and triterpenes. Malathion is an insecticide that helped to increase value and yields of Centella. asiatica by control the damage caused by crop pests. Study was done in MARDI Serdang to measure malathion residue in Centella. asiatica with different treatment methods using GC-MS. Six plots were randomly selected and samples were taken a day before, a day, three days and five days after the application of malathion. The samples were divided into treated (soaked in tap water and salted water), and untreated groups. The sample was extracted through the liquid-liquid extraction and underwent a clean-up process by a silica gel. The residues were found in; three samples treated with salt water (A1=19.78 mg/kg, C1=8.53 mg/kg and E1=0.99 mg/kg), one sample treated with tap water (E1=0.44 mg/kg) and two unwashed samples (E1=0.0053 mg/kg and F1=0.0077 mg/kg). Therefore the safest way to consume is by soaked with tap water compared with soaked in salt water and unwashed. However the malathion residue found were below the Maximum Residue Limits set up by US EPA.

Background and purpose: Widespread use of plant pesticides in agriculture resulted in increasing concerns about pesticide hazards. In this research, the residual levels of pesticides in melons were evaluated by GAS CHROMATOGRAPHY-MASS SPECTROMETRY (GC-MS).Materials and methods: In this study, 75 samples of melons in Tehran market were used for simultaneous analysis of a variety of common pesticides in melons by GC/MS in two modes of scanning and SIM (Selected Ion Monitoring).Results: Among the samples, 8% were found with different types of residual pesticides, including pirimicarb (0.007 mg/g), dimethoate (0.03 mg/g), metalaxyl (0.015 mg/g), Alpha-endosulfan (0.012 mg/g), and permethrin (0.008 mg/g). All contaminations were less than the limits set by the Codex and the United States of America (P<0.05).Conclusion: The standard limitations of pesticides in melons are not yet recommended in Iran, so, current findings could be used by authorities in determining these residual limits.