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.

Multidetector systems have been widely used in GC for many years. Even though the mass spectrometer is still the most popular GC detector in the case of complex samples, a multidetector system can provide all the information needed for the confirmation purposes. This review describes various GC setups for multidetector analysis, and modern systems available on the market. An overview of the application of multidetector systems with various detectors in GC is also enclosed. The most popular system involves parallel detectors and a post-injector or postcolumn effluent splitter.

The basic concept of a sample preparation method is to convert a real matrix into a sample in a format that is suitable for analysis. Some GASeous, liquid, and volatile solid samples are suitable for direct injection to GAS CHROMATOGRAPHY instrument. But most samples are not ready to introduce directly into the column of GC. such as removal of serious interferences from the sample, increase of analyte concentration, convert the analyte into a more suitable form to detect and determine, using smaller initial sample sizes and finally achieving higher selectivity. This article discusses various types of analyte extraction, cleanup and concentration. Extraction methods can include classic techniques such as purge and trap, static headspace extraction, and liquid-liquid extraction to newer techniques such as solid phase microextraction, membrane extraction, single drop microextraction and superheated water extraction.

In this paper various factors that effected on separation of mono and di substituted nitro toluene compounds was investigated by GAS CHROMATOGRAPHY method and optimum separation condition was reported for 2-nitrotolouen (2NT), 4-nitrotolouen (4NT), 2,3-dinitrotolouen (2,3DNT),  2,4-dinitrotolouen (2,4DNT), 2,6-dinitrotolouen (2,6DNT)  and 3,4-dinitrotolouen (3,4DNT) compounds. Optimum carrier GAS flow rate and injection volume was 20-30 ml.min-1 and 0.3 t1, respectively. Isothermal separation method wasn’t accepted for given good results and then programming mode (T1=80 OC, t1=6S, scan rate=30, T2=240, t2=6s) was used.

In this study, two oil samples from Asmari and Sarvak reservoirs (well No#23) in Pazanan oil field and one oil sample from Khalij reservoir (well No#1) in Khaviz oil field were subjected to geochemical analyses using GAS CHROMATOGRAPHY (GC) and GAS CHROMATOGRAPHY Mass-Spectrometry (GC/MS) techniques. Quantitative assessment of the oil components using liquid CHROMATOGRAPHY method revealed that oil samples have a greater amount of saturated hydrocarbon component than the aromatic and polar. Classification of the crude oil samples based on different components shows that the Asmari and Sarvak reservoir oil in Pazanan oil field and Khalij reservoir oil in Khaviz oil field are paraffinic, mainly paraffinic to paraffinic-naphthenic and paraffinic – naphthenic respectively. The biomarker ratio obtained from C29 Sterane β β ∕ (β β +α α ) versus C29 Sterane 20S/(20S+20R) diagram demonstrates that the oil samples were produced at the maximum stage of the oil producing window and have relatively high thermal maturity. The DBT/Phen versus Pr/Ph diagram shows that the Asmari oil samples have been produced from carbonate-shale, and Sarvak and Khlij oil samples have been produced from carbonate-marl source rocks. Also, triangular C27, C28, C29 sterane diagram indicates that the source rocks have been deposited in open marine to parallic environment. Also, oil has been generated from organic matter with type II kerogen as inferred from Pr/nC17 versus Ph/nC18 diagram. The proximity of the Carbon Preference Index (CPI) to the number 1, indicates high maturity level for source rocks. Absence of oleanane biomarker in oil samples suggests that oils be produced from lower-Cretaceous source rocks. Oil-oil correlation using distinctive biomarkers allowed to plot the stellar graph. Finally, the even/odd ratio of normal alkanes determines that the oil samples from Asmari, Sarvak, and Khalij reservoirs have been produced from a variety source rocks.

Background and Aim: Nowadays, drug abuse is a major problem in societies and, detection of drugs in urine is very important. In general, immunoCHROMATOGRAPHY (ICG) and thin-layer CHROMATOGRAPHY (TLC) are routine methods for the detection of drugs in urine. These methods are rapid and economical, but their accuracy rates for detection of drugs at lower concenterations are low (< cut off). Morphine, amphetamine and methamphetamine, are conventional drugs that are widely used. The purpose of this study was to compare immunoCHROMATOGRAPHY, thin layer CHROMATOGRAPHY (TLC) and GAS CHROMATOGRAPHY (GC) methods for detection of morphine, amphetamine and methamphetamine in the spiked healthy human urine samples and urine of addicted people. We also compared their detection limits with one another. Materials and Methods: This was an experimental study and included urine samples obtained from healthy and addicted people referring to the laboratory of the 7th of Tir marriage counseling center in East Azerbaijan Province, in June 2016. After collection of urine samples, samples obtained from healthy people were spiked with various concentrations of morphine, amphetamine and methamphetamine. Then, all samples were tested by immunoCHROMATOGRAPHY, TLC and GC methods for the detection of morphine, amphetamine and methamphetamine. Results: Results showed that ICG and TLC methods can not detect lower concentrations (< cut off) of morphine, amphetamine and methamphetamine. While, GC can easily detect them in urine samples, even in lower concentrations (< cut off) and has a high detection limit and accuracy rate. Conclusion: It can be concluded GC method is a powerful and accurate technique for detection of drugs in urine samples.

This paper verifies the quality of determination of fatty acids in detection of adulteration of olive oil with certain vegetable oils.2% adulteration in canola oil can be detected based on gadoleic acid in the quantity of more than 0.4 and, the detection of 4% adulteration in canola oil is based on linolenic acid in the quantity of more than 1, 10% adulteration in soybean oil can be detected based on linolenic acid in the quantity of more than 1 and the detection of 4% adulteration in sunflower oil is based on behnic acid in the quantity of more than 0.2 are possible. But the detection of adulteration Of pomace oil is based on free fatty acids profile which Is not possible.

The surface characteristics of treated plup paper fibre were investigated using inverse GAS CHROMATOGRAPHY (IGC). The surface of the pulp paper fibres was modified with γ-aminopropyl-triethoxysilane, dichlorodiethylsilane and vinyl triethoxysilane. The effectiveness of these surface treatments was monitored by the IGC adsorption curves using n-alkanes and acid-base probes. The empirical acid (KA) and base (KD) characteristics (i.e., electron donor / acceptor abilities) of untreated and treated pulp papers fibres were determined using Schultz’s method and were correlated with the surface chemical compositions determined from Fourier transform infrared spectroscopy (FTIR) technique. The results indicated that the surface of untreated pulp paper fibres had an acidic characteristic due the to the electron acceptor character of the hydroxyl protons. γ-Aminopropyl triethoxysilane produced a basic surface behaviour attributed to the electron donor ability of the amino groups. Dichlorodiethylsilane produced a strong acidic surface attributed to the highly electronegative nature of the chlorine atoms. When the fibres were treated with vinyl triethoxysilane, an acidic surface was observed.

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.

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.