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An inside-needle extraction method was developed through thermal polymerization of atrazine-molecularly imprinted polymer (MIP) on the internal surface of a stainless steel hollow needle, which was oxidized and silylated. The fabricated coating (MIP layer) for the needle was durable and showed very good chemical and thermal stability. It could be mounted on a glass syringe and be directly coupled with gas chromatographic (GC) systems. The parameters being effective on the coating and extraction processes, namely nature of oxidizing agent, silylation time, nature and amount of porogen, template-to-MIP components ratio, polymerization time and temperature, sample volume, flow rate, pH and ionic strength of the sample were investigated and optimized. The extraction needle showed high selectivity as well as a great extraction capacity for triazines. The extraction of atrazine, simazine, cyanazine, ametryn, prometryn and terbutryn using the fabricated extraction needle and followed by GC analysis resulted in detection limits of 2.6, 21, 24, 32, 38 and 42 ng mL−1, respectively. The fabricated needle proved to be applicable to the analysis of real samples by comparing the results obtained for non-spiked and spiked samples of grape juice, tap water and groundwater.

A monolithic solid-phase microextraction (SPME) fiber was fabricated based on a molecularly imprinted polymer which could be coupled with gas chromatography for extraction, pre-concentration and determination of methamphetamine (MAMP). Methacrylic acid, ethylene glycol dimethacrylate and MAMP play the roles of functional monomer, cross-linker and template, respectively. The effective factors influencing the polymerization and extraction procedures were investigated and will be detailed here. The fabricated fiber was firm, inexpensive, stable, selective and durable which gives it vital importance in SPME. Selectivity of the fabricated fiber in relation to the template in solution containing MAMP, related and unrelated compounds was also investigated. Under the optimum conditions, the calibration plot was linear in the range of 50–3,500 ng mL−1 (r2 = 0.997). The high extraction efficiency was obtained for MAMP giving a detection limit of 14 ng mL−1. The fabricated fiber was successfully applied to SPME of MAMP from human saliva samples followed by gas chromatography-flame ionization detector analysis.

Introduction: A simple, rapid and low cost method for enrichment of volatile organic compounds (VOCs) from exhaled breath (EB) is presented. Methods: A 1000 mL home-made extraction device was filled with EB. The VOCs were extracted and condensed in 0.5 mL acetone. Recognition of volatiles in the real studied EB samples was performed by a GC-MS. Results: The method displays an extraction efficiency of >86% with the enrichment factor of 1929 for octanal. Limits of detection and quantification, and linear dynamic range were 0.008, 0.026 and 0.026-400 ng/mL respectively. Analysis of real samples showed the existence of more than 100 compounds in EB of healthy volunteers and patients with lung cancer before and after treatment. Exhaled octanal concentration was significantly higher in lung cancer patient than in healthy volunteers and lung cancer patient after treatment. Conclusion: Having used the proposed approach, high extraction recovery (up to 86%) was attained for the lung cancer marker, octanal, as an important biomarker. Our findings on smaples of EB of healthy controls and patients with lung cancer before and after treatment provide complelling evidence upon the effectiveness of the developed method.

This article aims to provide a new and fast method for differentiation of inks on a questioned document. The data acquisition was carried out by designing specific image analysis software for evaluating thin layer chromatograms (TLC-IA). The ink spot was extracted from the document using methanol and separated by TLC using plastic sheet silica gel 60 without fluorescent indicator, and a mixture of ethyl acetate, ethanol, and water (70:35:30, v/v/v) as mobile phase. To discriminate between different pen inks, new software was designed on the basis of intensity profile of red, green, and blue (RGB) characteristic. In practice, after development of chromatogram, the chromatograms were scanned by ordinary office scanner, intensity profiles of RGB characteristics on the development straight of each sample were produced and compared with the mentioned software. RGB profiles of ballpoint inks from various manufacturers showed that the patterns in most cases were distinctly different from each other. This new method allowed discriminating among different pen inks with a high reliability and the discriminating power of 92.8%. Blue ballpoint pen inks of 41 different samples available on the local market were successfully analyzed and discriminated.

We have developed a solvent-free and sensitive method for the identification and quantification of methamphetamine (MAMP), amphetamine (AMP) and ecstasy (MDMA) in human urine. It is based on the use of an inside-needle adsorption trap (INAT) and a molecularly imprinted polymer (MIP). The MAMP-MIP layer was coated on the internal surface of a hollow stainless steel needle, which was oxidized and silylated. It was used as the extraction needle. A model solution containing the drugs was slowly passed through the extraction needle. After adsorption of the analytes, the needle was directly transferred to the injector of a gas chromatograph, where the analytes were thermally desorbed, separated by GC, and detected with a flame ionization detector. The method does not require an extraction solvent, is fast and simple. The linear range of the calibration graphs are rather wide, and the limit of detection and the limit of quantification (LOQ) for MAMP are 12 and 40 ng mL −1 , respectively. The relative standard deviations (RSD%) for six repeated experiments (at 500 ng mL −1 of MAMP) is 4.9 %. The relative recoveries obtained for MAMP in spiked human urine samples are in the range of 81–93 %. Graphical Abstract Figure Typical chromatograms corresponding to the extraction of MAMP, AMP and MDMA in the optimum condition from human urine sample. Lower chromatogram (I) belong to non-spiked samples after extraction using MAMP-MIP coated needle and the other chromatograms, (II) and (III), are related to spiked samples with MAMP, AMP and MDMA (each 0.5 μg mL −1 ) and extraction using the NIP-coated needle and MAMP-MIP coated needle, respectively.

Summary This paper presents a new method based on thin-layer chromato-graphic separation, and image analysis (TLC-IA) of saffron colorant compounds for the discrimination of saffron from different origins. The color compounds of dried and ground saffron stigmas are extracted and separated by thin-layer chromatography at optimum conditions. After chromatographic development, the chro-matograms are photographed, and intensity profiles of RGB characteristics are produced and processed by specially designed image analysis software. The main factors such as the extraction procedure of color compounds, chromatographic system (stationary and mobile phase), and designing of image analysis software are described. This method includes a new and fast data acquisition and does not require expensive instruments. The method also allows for comparison of different types of saffron using R F values, color range, and intensity of the separated color components. This method is successfully applied to determine the saffron from different regions of Iran and various adulteration colorants.

We report on a simple, rapid, and efficient method for the extraction of volatile organic compounds (VOCs; including methanol, tetrahydrofuran, 2-hexanone and benzene) from air and solid samples. The system is based on the use of a laboratory-made syringe as the extractor. The needle of the syringe is placed in a chamber cooled by liquid nitrogen. The tip of the needle is placed in the headspace of a vial containing the sample. The headspace components then are circulated with a pump to pass the needle, and this results in freeze-trapping of the VOCs on the inner surface of the needle. The circulation of the headspace components is continued for 15 min, and the syringe is then removed and placed in a GC injector. The effects of volume of the sample vial, headspace flow rate, temperature and time of extraction and desorption were optimized. The overall time for sampling and analysis is <30 min. The method displays an extraction efficiency of >80%) and a good sample transfer efficiency into the GC column due to the absence of a sorbent inside the needle. No carry-over was observed after 30 s desorption at 260 °C. An external standard method was used for quantitative analysis. The relative standard deviation values are below 10% and the limits of detection range from 1.3 to 4.6 ng g −1 . Fiugre The scheme of sorbentless cryogenic needle trap device