Optimization of the in-needle extraction device for the direct flow of the liquid sample through the sorbent layer

Needle trap device technique: From fabrication to sampling

Needle Trap Device (NTD) as a novel, versatile, and eco-friendly technique has played an important role in analytical and environmental chemistry. The distinctive role of this interdisciplinary technique can be defended through the sampling and analysis of biological samples and industrial pollutants in gaseous and liquid environments. In recent years, significant efforts have been made to enhance the performance of the needle trap device resulting in the development of novel extraction routes by various packing materials with improved selectivity and enhanced adsorption characteristics. These achievements can lead to the facilitated pre-concentration of desired analytes. This review tries to have a comparative and comprehensive survey of the three important areas of NTD technique: I) Fabrication and preparation procedures of NTDs; II) Sampling techniques of pollutants using NTDs; and III) Employed materials as adsorbents in NTDs. In the packing-material section, the commercial and synthetic adsorbents such as carbon materials, metal-organic frameworks, aerogel, and polymers are considered. Furthermore, the limitations and potential areas for future development of the NTD technique are presented.

The Effects of Various Food Products on Bisphosphonate's Availability

The bioavailability of orally administered bisphosphonates is very low (<1%) due to their short absorption window in the proximal duodenum and high affinity for food. Food ingredients are able to bind the drug, but the presence of food extends the residence time of bisphosphonates in the absorption window. Therefore, the main goal of this study is to select a group of food products that are characterized by low binding affinity to bisphosphonates and thus will not reduce their availability upon concomitant administration. For this purpose, a combination of three methods was applied: (1) evaluation of sorption capacity for rows of digested food samples in a simulated intestinal environment; (2) evaluation of drug availability in simulated chyme; and (3) evaluation of drug availability using a simulating needle device. The results indicate that food products such as egg white and white bread are most suitable for consumption during oral bisphosphonate intake.

Development of a new needle trap-based method for the determination of some volatile organic compounds in the indoor environment

Volatile Organic Compounds (VOCs) are a large group of chemicals mostly found in indoor environments such as homes and workplaces. Long term exposure to certain VOCs can cause symptoms in some individuals and therefore, monitoring and controlling air quality can help better manage chronic respiratory diseases. In this study, we aimed to develop an easy-to-use, economical, in house needle trap-based methodology to detect certain VOCs to be used for public and occupational health. For this purpose, a multi-bed (packed with PDMS/Carbopack-X/Carboxen-1000) needle trap device (NTD) was utilized for sampling, enrichment, and injection of the VOCs into the gas chromatography. The performance of the developed method was investigated for the analysis of the group known as BTEX (benzene, toluene, ethylbenzene and xylene). Operational and instrumental parameters such as sampling flow rate and relative humidity, desorption time and temperature were optimized, and the analytical figures of merit of the proposed method have indicated that very low levels of BTEX in air samples can be easily determined by this new method. Overall results have shown that multi-bed NTD offers a high sensitive procedure for sampling and analysis of BTEX in concentration range of 0.002-0.298 mg/m³ in indoor air.

Determination of bisphosphonates anti-resorptive properties based on three forms of ceramic materials: Sorption and release process evaluation

There is a strong need to search for more effective compounds with bone anti-resorptive properties, which will cause fewer complications than commonly used bisphosphonates. To achieve this goal, it is necessary to search for new techniques to characterize the interactions between bone and drug. By studying their interaction with hydroxyapatite (HA), this study used three forms of ceramic materials, two of which are bone-stimulating materials, to assess the suitability of new active substances with anti-resorptive properties. In this study, three methods based on HA in loose form, polycaprolactone/HA (a polymer-ceramic materials containing HA), and polymer-ceramic monolithic in-needle extraction (MINE) device (a polymer inert skeleton), respectively, were used. The affinity of risedronate (a standard compound) and sixteen aminomethylenebisphosphonates (new compounds with potential antiresorptive properties) to HA was defined according to the above-mentioned methods. Ten monolithic materials based on 2-hydroxyethyl methacrylate/ethylene dimethacrylate are prepared and studied, of which one was selected for more-detailed further research. Simulated body fluids containing bisphosphonates were passed through the MINE device. In this way, sorption-desorption of bisphosphonates was evaluated using this MINE device. The paper presents the advantages and disadvantages of each technique and its suitability for assessing new active substances. All three methods allow for the selection of several compounds with potentially higher anti-resorptive properties than risedronate, in hope that it reflects their higher bone affinity and release ability.

Poly(vinyl alcohol)/hydroxyapatite Monolithic In-Needle Extraction (MINE) device: Preparation and examination of drug affinity

Polymer-ceramic materials based on poly(vinyl alcohol) (PVA) and hydroxyapatite were applied as sorption material in Monolithic In-Needle Extraction (MINE) device. The presented device provides new possibilities for the examination of bisphosphonates affinity for bone and will be a helpful tool in evaluation of potential antiresorptive drugs suitability. A ceramic part of monoliths was prepared by incorporation of hydroxyapatite (HA) into the reaction mixture or by using a soaking method (mineralization of HA on the PVA). The parameters of synthesis conditions were optimized to achieve a monolithic material having the appropriate dimensions after the soaking process enabling placing of the monolithic material inside the needle. Furthermore, the material must have had optimal dimensions after the re-soaking process to fit perfectly to the needle. Among the sixteen monolithic materials, eight of them were selected for further study, and then four of them were selected as a sorbent material for the MINE device. The material properties were examined on the basis of several parameters: swelling ratio, initial mass reversion and initial diameter reversion, mass growth due to the HA formation, and antiresorptive drug sorption. The MINE device might be then used as a tool for examination of interactions between bisphosphonate and bone. The simulated body fluid containing sodium risedronate (RSD) as a standard compound was passed through the MINE device. The obtained device allowed for sorption about 0.38mg of RSD. The desorption process was carried out in five steps allowing insightful analysis. The MINE device turned out to be a helpful tool for determination of the bisphosphonates affinity to the ceramic part of sorbent (hydroxyapatite) and to assess the usefulness of them as antiresorptive drugs in the future.