Perspectives and challenges of on-site quantification of organic pollutants in soils using solid-phase microextraction

This study explores the current state-of-the-art progress toward on-site quantification of organic pollutants in soils with solid-phase microextraction (SPME). In spite of many available methods, only few publications report on-site analyses of soil samples by SPME. To date, the only application of SPME for the on-site quantification of organic pollutants in soil has been devoted to trichloroethylene. The problem of matrix effects limiting quantification by external standard calibration is discussed. Efficiencies of available approaches for decreasing and controlling matrix effects are evaluated and compared. SPME from a soil sample headspace with internal standard calibration was identified as one of the promising approaches to achieve fast, simple, precise, and accurate on-site quantification of a wide range of organic pollutants in soil. Cold-fiber SPME has a significant development potential, because it is capable of providing lowest detection limits together with a minimum matrix effect. Perspectives for future development of the field are outlined

Quantification of BTEX in Soil by Headspace SPME–GC–MS Using Combined Standard Addition and Internal Standard Calibration

There is a great demand for simple, fast and accurate methods for quantification of volatile organic contaminants in soil samples. Solid-phase microextraction (SPME) has a huge potential for this purpose, but its application is limited by insufficient accuracy caused by a matrix effect. The aim of this research was to develop the method for BTEX quantification in soil using combined standard addition (SA) and internal standard (IS) calibration. Deuterated benzene (benzene-d6) was used as the internal standard for all analytes. The optimized method includes spiking replicate samples with different concentrations of BTEX standards and the same concentration of benzene-d6, equilibration of soil samples at 40 °C during 2 h, and SPME–GC–MS analysis. Precision and accuracy of IS and SA methods were compared on different soil matrices. Combined SA + IS method provided more precise calibration plots compared to the conventional SA calibration. The SA + IS calibration provided more precise and accurate results compared with a reference method based on solvent extraction followed by GC–MS when applied to BTEX quantification in real soil samples (spiked with diesel fuel and aged). Recoveries of BTEX from soil samples spiked with known concentrations of analytes using the developed method were in the range of 73–130% with RSD values less than 15% for all BTEX. The proposed simultaneous standard addition and internal standard approach can be advantageous and adopted for improved quantification of other toxic VOCs in soil

Quantification of naphthalene in soil using solid-phase microextraction, gas-chromatography with mass-spectrometric detection and standard addition method

Development of simple, fast and accurate methods for quantification of volatile organic compounds (VOCs) in soil samples is important for providing greater efficiency of analytical laboratories in Kazakhstan and other developing countries. Naphthalene is a model polycyclic aromatic hydrocarbon (PAH), belonging to a group of compounds of significant concern due to environmental impact. Solidphase microextraction (SPME) is an optimal method for solvent-free automated sample preparation for determination of VOCs in environmental samples. In this work, the method for quantification of naphthalene in soil based on headspace SPME, gas chromatography with mass spectrometric detection, and standard addition calibration was developed. The parameters of SPME and sample equilibration after spiking with standards were optimized for better control of the soil matrix effect. The SPME temperature 80 °C provided the greatest accuracy of naphthalene responses for soils with different matrix and humidity. Equilibration of soil samples after spiking with standards for 6 h at 80 °C provided stabilization of responses in soils with different matrix and water content. The greatest accuracy and precision were achieved after equilibration of the samples for 8 h. The method provides recoveries of 105-119% in the concentration range 0.01-0.1 ng g-1 with detection limit 0.001 ng g-1. The developed method was applied for quantification of naphthalene in real soil samples collected in Almaty, Kazakhstan. The measured concentration of naphthalene in real soil samples varied in the range of 1.4 to 47 ng g-1. In five out of ten collected soil samples concentration exceeded a maximum permissible concentration of 15 ng g-1.This article is published as Orazbayeva, D., B. Kenessov, and J.A. Koziel. "Quantification of naphthalene in soil using solid-phase microextraction, gas-chromatography with mass-spectrometric detection and standard addition method." International Journal of Biology and Chemistry 11, no. 1 (2018): 4-11. Posted with permission.</p

Problems of establishment and activity of the antituberculosis service in Kazakhstan during Virgin Lands campaign (early 1960s)

The paper notes that after the formation of the Virgin Lands area in December 1960, the local health authorities faced a pressing issue of solving the problems of tuberculosis spread among the local population, as well as people resettled there. Tuberculosis, like other infectious diseases, was widespread in Kazakhstan. The establishment of tuberculosis dispensaries and the creation of fluorography and X-ray machines have provided an opportunity to expand preventive measures for the examination and detection of tuberculosis patients. The health authorities of the Virgin Lands area considered work in this direction as improving the quality of medical care. However, the quality of treatment was often reduced due to the facts that the treatment regimen was violated in several dispensaries, there were not enough specialists, control over the full and long-term treatment of tuberculosis patients was not imposed. The authors of the paper concluded that insufficient and not universal organization of medical care was one of the reasons for the high incidence of tuberculosis among the population

Perspectives and challenges of on-site quantification of organic pollutants in soils using solid-phase microextraction

This study explores the current state-of-the-art progress toward on-site quantification of organic pollutants in soils with solid-phase microextraction (SPME). In spite of many available methods, only few publications report on-site analyses of soil samples by SPME. To date, the only application of SPME for the on-site quantification of organic pollutants in soil has been devoted to trichloroethylene. The problem of matrix effects limiting quantification by external standard calibration is discussed. Efficiencies of available approaches for decreasing and controlling matrix effects are evaluated and compared. SPME from a soil sample headspace with internal standard calibration was identified as one of the promising approaches to achieve fast, simple, precise, and accurate on-site quantification of a wide range of organic pollutants in soil. Cold-fiber SPME has a significant development potential, because it is capable of providing lowest detection limits together with a minimum matrix effect. Perspectives for future development of the field are outlined.This is a manuscript of an article published as Kenessov, Bulat, Jacek A. Koziel, Nadezhda V. Bakaikina, and Dina Orazbayeva. "Perspectives and challenges of on-site quantification of organic pollutants in soils using solid-phase microextraction." TrAC Trends in Analytical Chemistry 85 (2016): 111-122. DOI: 10.1016/j.trac.2016.04.007. Posted with permission.</p

Идентификация и определение органических загрязнителей в воздухе города Астана с использованием твердофазной микроэкстракции

Метод твердофазной микроэкстракции в сочетании с газовой хроматографией с масс- спектрометрическим детектированием был использован для количественного определения бензола, толуола, этилбензола и о-ксилола (БТЭК), полициклических ароматических углеводородов (ПАУ), и идентификации летучих органических соединений (ЛОС) в атмосферном воздухе города Астана, Казахстан. Скрининг образцов воздуха, отобранных в городе Астана, показал наличие моно- и полициклических ароматических углеводородов, алканов, алкенов, фенолов и бензальдегидов. Во всех исследованных пробах были обнаружены БТЭК и ПАУ. Концентрации нафталина, в 5-7 раз превышающие ПДК, найдены во всех исследованных образцах воздуха. Средние концентрации нафталина в исследованных образцах составили 18,4 мкг/м3; аценафтилена – 0,54 мкг/м3; аценафтена – 1,63 мкг/м3; флуорена – 0,79 мкг/м3; антрацена – 3,27 мкг/м3; фенантрена – 0,22 мкг/м3; флуорантена – 0,74 мкг/м3; пирена – 0,73 мкг/м3. Средние концентрации бензола, толуола, этилбензола и о-ксилола в исследованных образцах составили 31,1; 84,9; 10,8 и 11,6 мкг/м3, соответственно. На основании статистического анализа результатов определения БТЭК и ПАУ был предположен основной источник загрязнения ими воздуха города – выбросы автотранспорта

Quantification of BTEX in Soil by Headspace SPME–GC–MS Using Combined Standard Addition and Internal Standard Calibration

There is a great demand for simple, fast and accurate methods for quantification of volatile organic contaminants in soil samples. Solid-phase microextraction (SPME) has a huge potential for this purpose, but its application is limited by insufficient accuracy caused by a matrix effect. The aim of this research was to develop the method for BTEX quantification in soil using combined standard addition (SA) and internal standard (IS) calibration. Deuterated benzene (benzene-d6) was used as the internal standard for all analytes. The optimized method includes spiking replicate samples with different concentrations of BTEX standards and the same concentration of benzene-d6, equilibration of soil samples at 40 °C during 2 h, and SPME–GC–MS analysis. Precision and accuracy of IS and SA methods were compared on different soil matrices. Combined SA + IS method provided more precise calibration plots compared to the conventional SA calibration. The SA + IS calibration provided more precise and accurate results compared with a reference method based on solvent extraction followed by GC–MS when applied to BTEX quantification in real soil samples (spiked with diesel fuel and aged). Recoveries of BTEX from soil samples spiked with known concentrations of analytes using the developed method were in the range of 73–130% with RSD values less than 15% for all BTEX. The proposed simultaneous standard addition and internal standard approach can be advantageous and adopted for improved quantification of other toxic VOCs in soil.This is a manuscript of an article published as Orazbayeva, Dina, Bulat Kenessov, Jacek A. Koziel, Dayana Nassyrova, and Nadezhda V. Lyabukhova. "Quantification of BTEX in Soil by Headspace SPME–GC–MS Using Combined Standard Addition and Internal Standard Calibration." Chromatographia 80, no. 8 (2017): 1249-1256. The final publication is available at Springer via DOI: 10.1007/s10337-017-3340-0. Posted with permission.</p

Концентрации бензола, толуола, этилбензола и о-ксилола в почвах и атмосферных осадках в городах Алматы и Астана

БТЭК (бензол, толуол, этилбензол и ксилол) являются одной из наиболее опасных групп органических токсикантов по объемам выбросов и рискам для здоровья населения. БТЭК присутствуют практически во всех техногенных и природных объектах. Наибольший риск здоровью населения представляет загрязнение БТЭК в городах, характеризующихся высокими плотностями населения и объемами выбросов БТЭК в окружающую среду. Целью данной работы было определение концентраций бензола, толуола, этилбензола и о-ксилола в образцах почв и атмосферных осадков, отобранных в городах Алматы и Астана. Скрининг и количественное определение аналитов проводили методом газовой хроматографии с масс- спектрометрическим детектированием. В качестве пробоподготовки использовали метод твердофазной микроэкстракции. В образцах почв, отобранных в городах Алматы и Астана, концентрации бензола составили от 25,7 до 455 нг/г, толуола - от 9,9 до 375 нг/г, этилбензола - от 1,8 до 386 нг/г, о-ксилола - от 2,4 до 217 нг/г. Концентрации БТЭК в образцах атмосферных осадков варьировались в диапазоне 8,2-21,2 нг/г для бензола; 0,8-5,1 нг/г для толуола; 0,1-1,1 нг/г для этилбензола; и 0,2-0,5 нг/г для о-ксилола. Содержание БТЭК в исследованных почвах в городах Алматы и Астана в среднем в десятки раз выше, чем в европейских городах

Polymeric ionic liquid sorbent coatings in headspace solid-phase microextraction: A green sample preparation technique for the determination of pesticides in soil

In this work, a green approach utilizing novel polymeric ionic liquid (PIL) coatings for headspace solid-phase microextraction (HS-SPME) of four current-use pesticides from soil samples was studied for the first time. Epoxiconazole, fluroxypyr, metribuzin, and oxyfluorfen were the target pesticides. Three PIL coatings containing 1-vinylbenzyl-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide (PIL1 and PIL2) and 1-vinyl-3-(10-hydroxydecyl)imidazolium bis[(trifluoromethyl)sulfonyl]imide (PIL3) monomers, and 1,12-di(3-vinylbenzylimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide (PIL1) and 1,12-di(3-vinylbenzimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide (PIL2 and PIL3) crosslinkers were employed in this study. The performance of these PIL coatings was evaluated and compared with commercial SPME coatings based on polydimethylsiloxane/divinylbenzene (PDMS/DVB) and polydimethylsiloxane (PDMS) at the different extraction temperatures (50–90 °C) and sampling times (15–60 min). HS-SPME at 90 °C for 60 min provided the highest sensitivity and adequate reproducibility for the majority of analytes. Despite having a lower thickness, PIL2 and PIL3 coatings provided similar extraction effectiveness of analytes, and 24–247% higher coating volume-normalized responses compared to the commercial PDMS/DVB coating. The use of the PIL1 sorbent coating resulted in excellent linearity (R2 = 0.995–0.999) and lower detection limits (0.06–0.4 ng g−1) for all analytes. The optimized method provides acceptable recoveries of spiked concentrations with better performance (84–112%) achieved with the PIL1 coating. Compared to other known methods for target pesticides in soil, the proposed method provides the highest compliance with the principles of green analytical chemistry evaluated using Analytical Eco-Scale and Green Analytical Procedure Index tools