Showing 3 results for Needle Trap
Shiva Soury, Abdulrahman Bahrami, Saber Alizadeh, Farshid Ghorbani Shahna, Davood Nematollahi,
Volume 10, Issue 2 (5-2020)
Abstract
Introduction: In this study, Zn3(Btc)2 (metal organic framework) sorbent was introduced for sampling of Benzo[a]pyren from the air. The purpose of this study was to develop the sampling and analysis method by needle trap, with no sample preparation step.
Material and method: Zn3(Btc)2 sorbent was electrochemically synthesized and its properties were specified by FTIR, FE-SEM, and PXRD techniques. A glass chamber with a temperature of 120°C was used to make the certain concentration of Benzo[a]pyren. Factors affecting the efficiency of needle trap were evaluated and optimized using a response surface method considering a specific operating interval to achieve the highest efficiency. The performance of the proposed method was also investigated using the real samples.
Results: The highest desorption efficiency of Benzo[a]pyren was obtained when using the needle trap containing Zn3 (Btc)2 sorbent at 379°C and 9 min retention time. No significant reduction was observed in the analyte concentration by maintaining the sampler for 60 days. The limit of detection and limit of quantification of Benzo[a]pyren were obtained 0.01 and 0.03 mg/m3, respectively. The percentage of standard deviation of the measured values of Benzo[a]pyren in diesel exhaust was calculated 4.1%.
Conclusion: The highest desorption efficiency of Benzo[a]pyren was obtained when using the needle trap containing Zn3 (Btc)2 sorbent at 379°C and 9 min retention time. No significant reduction was observed in the analyte concentration by maintaining the sampler for 60 days. The limit of detection and limit of quantification of Benzo[a]pyren were obtained 0.01 and 0.03 mg/m3, respectively. The percentage of standard deviation of the measured values of Benzo[a]pyren in diesel exhaust was calculated 4.1%.
Masoomeh Vahabi Shekarloo, Siamak Ashrafi Barzideh, Rezvan Zendehdel ,
Volume 13, Issue 3 (9-2023)
Abstract
Introduction: Several extraction techniques have been developed in recent years to determine the concentration of volatile metabolites in a biological sample. This study conducted with the aim of using the needle trap device- molecularly imprinted polymer (NTD-MIP) for the co-extraction of n-hexane and methyl ethyl ketone (MEK) in the urine matrix.
Material and Methods: Characterization of MIP was investigated by fourier-transfer infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), and brunauer–emmett–teller (BET). The response surface methodology - central composite design (RSM-CCD) was used to optimize the extraction conditions of n-hexane and MEK with the input variables of absorption temperature, absorption time, salt percent, and stirring speed. Method validation was performed with determination of the precision, accuracy, the limit of detection (LOD), limit of quantification (LOQ), and dynamic linear range.
Results: The optimum conditions were an extraction time of 60 min, an absorption temperature of 65 °C, 22% of salt, and a stirring speed of 250 rpm. The linear ranges of n-hexane and MEK were determined in ranges of 30-500 and 30-4000 µg/L, respectively. The intra-day and enter-day relative standard deviation were evaluated in the range of 3 to 10 and 1 to 7, respectively. The average recovery of n-hexane and MEK were estimated 99.3 ± 0.8 and 99 ± 0.9, respectively.
Conclusion: The HS-NTD method is suggested as a suitable method for determining very low amounts of MEK in urine along with n-hexane.
Saleh Qahri Saremi, Nabiollah Mansouri, Mahmoud Heidari, Marzieh Shekarriz, Homayon Ahmad Panahi,
Volume 15, Issue 2 (7-2025)
Abstract
Introduction: Evaluation of air pollutants using green microextraction methods that do not require solvents and allow for sampling and analysis in a single step has received attention. In this study, the needle trap microextraction method was developed and the hydroxyl fullerene adsorbent was used for benzene sampling in air.
Material and Methods: Needle traps of identical length were filled with the selected adsorbent, and a standard chamber was used to generate specific benzene concentrations for sampling. Subsequently, the variables influencing the performance of the needle trap—specifically, sampling and desorption parameters—were optimized to achieve maximum efficiency using response surface methodology and Design Expert 11 software. Finally, the efficiency of the developed method was evaluated in a real-world environment and compared with the NIOSH 1501 method.
Results: Sampling temperature and humidity had an inverse relationship with the peak response rate, such that the sampler performed better at low temperature and humidity. The adsorbent’s ability to retain the analyte, despite its high vapor pressure, was deemed satisfactory, with analyte loss after 5 days measured at 5%. The maximum desorption occurred at 275°C and 3 minutes. The instrumental and quantitative detection limits were calculated to be 0.011 µgL-1 and 0.029 µgL-1 of air, respectively. The relative standard deviation (RSD) as an indicator of the repeatability of the method under study was also 5.38%. In a comparative study, the performance of the needle trap was evaluated to be better than the NIOSH method.
Conclusion: The needle trap method and the hydroxyl fullerene nanostructure adsorbent have a good performance in sampling benzene in air and are recommended for occupational and environmental monitoring.
