0000000000043239
AUTHOR
D. Gallart-mateu
Ion mobility spectrometry as a fast analytical tool in benzalkonium chloride homologs determination.
Abstract A novel procedure is proposed for the determination by ion mobility spectrometry (IMS) of C 12 , C 14 and C 16 benzalkonium chloride (BAC) homologs. The proposed method requires minimum sample treatment and the measurement was made in less than one minute. A high sensitivity was obtained for BAC determination by IMS with limit of detection values from 37 to 69 µg L −1 . Accuracy of the proposed methodology was evaluated through the analysis of aqueous and alcoholic samples spiked with BAC at concentration levels from 0.002% to 20% (w/v), providing recovery values from 91% to 104%. BAC was determined in sanitary alcohols, nasal sprays, postharvest products, algaecides, and treated s…
Hard cap espresso extraction-stir bar preconcentration of polychlorinated biphenyls in soil and sediments.
Abstract A Nespresso © hard cap espresso machine has been employed for the quantitative extraction of polychlorinated biphenyls (PCBs) from sediments and soils. Sample extraction was performed from five grams of sample in less than 40 s, with 200 mL ethanol 40% (v/v) in water and PCBs were concentrated using stir bar sorptive extraction (SBSE) and determined by thermal desorption-gas chromatography-tandem mass spectrometry (TD-GC-MS-MS). Eleven PCB congeners (28, 52, 77, 80, 81, 101, 118, 138, 153,169, and 180) were determined in soils and sediments with limits of quantification in the 0.03–0.08 ng g −1 range. Extraction efficiency was established by the analysis of soil samples spiked with…
Implementing the contamination prevention programs in the pesticide industry by infrared spectroscopy.
Abstract An infrared spectroscopy based methodology has been successfully developed to implement contamination prevention programs in the pesticide industry. Sensitivity of the IR procedure, traditionally considered the Achilles Hell of the technique, has been improved by using a transmission cell with an open upper side, an internal volume of 35 µL and an optical pathlength of 0.5 mm, providing detection limits of 32 mg L−1 for folpet and 48 mg L−1 for cymoxanil. The manufacturing of folpet and cymoxanil was employed as an example and the IR methodology was validated for the implementation of contamination prevention programs in the pesticide industry. The swab test and rinsate method were…
Passive exposure to nicotine from e-cigarettes
A procedure based on the use of ion mobility spectrometry (IMS), after liquid-liquid microextraction (LLME), has been successfully employed for the determination of passive exposure to nicotine from cigarette and e-cigarette smoking. Nicotine has been determined in exhaled breath and oral fluids of both, active and passive smokers. The aforementioned studies, made in closed environments, evidenced that the exhaled breath after conventional blend cigarette smoke provides nicotine levels of the order of 220 ng per puff, in the case of experienced smokers, being exhaled only 32 ng in the case of e-cigarettes. On the other hand, the nicotine amount in oral fluids of passive vapers was between 8…
Conductimetric study of struvite crystallization in water as a function of pH
Abstract The main objective of this work was to investigate the best pH for phosphorus removal from synthetic aqueous solutions using chemical precipitation of struvite, at constant temperature. The experimental approach, developed in the present study, consisted to precipitate struvite in synthetic wastewater containing PO 4 3− , NH 4 + and Mg 2+ ions in an equal molar ratio, using a stirred tank with continuous monitoring by conductimetry, at 25 °C. Different laboratory experiments were used to evaluate the effects of pH in the range of 8.5 till 11.8, on size, shape, and purity of the precipitated crystals. Struvite crystals were characterized by Infrared spectroscopy (FTIR), scanning ele…
Preliminary results about the breath of passive smokers and vapers based on the use of portable air monitoring devices
Abstract Preliminary studies were made on the effect of both, classical smoking and electronic cigarettes (ECs) vaping, based on the quality of the indoor air and the breath of passive smokers. Portable air monitoring devices were used to evaluate carbon monoxide (CO), carbon dioxide (CO2), particulate materials (PM), formaldehyde and volatile organic compounds (VOCs) in indoor air and breath of active and passive smokers and vapers. As preliminary results, it can be observed that the major part of PMs liberated in classical smoking and ECs vaping correspond to the lowest size, which is the most dangerous for human health. However, the number of smallest PMs formed during vaping is around 5…
Fast authentication of tea tree oil through spectroscopy
Two new procedures, based on infrared spectroscopy in the near infrared (NIR) and mid infrared (MIR), have been developed for the authentication of tea tree oil (TTO) commercial samples. Infrared measurements were made on untreated samples by transmission NIR and attenuated total reflectance (ATR) followed by partial least square discriminant analysis (PLS-DA). These methods offer a fast and low cost alternative to enantiomeric two-dimensional gas chromatography coupled to mass detection usually employed to discriminate between authentic and non-authentic samples. In these studies, a set of 267 samples, including authentic and non-authentic labelled tea tree oil samples, were used to build …
Exposure of heat-not-burn tobacco effect on the quality of air and expiratory plume
Abstract The increasing interest to avoid the consumption of regular tobacco has lead in the development of several types of devices to decrease the effects of this practice on active and bystanders. In this work, the impact of the use of new heat-not-burn (HnB) devices has been evaluated and compared with that of regular cigarettes and electronic cigarettes (e-cigs). Portable monitoring devices were employed for CO, CO2, particulate matter (PM) and volatile organic compounds (VOCs) to evaluate the quality of indoor air and expiratory plume of both, active and passive, users during these practices. It can be noticed that the levels of VOCs in active HnB smokers expiratory air are five times…
The importance of incorporating a waste detoxification step in analytical methodologies
The introduction of a waste detoxification step in the analytical process was highlighted using, as example, the determination of copper in pesticide formulations using electrogravimetry, flame atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy. This quantitative study showed the improvement of the previously mentioned analytical methods, from a green perspective, after addition of electrodeposition or neutralization steps to the analytical process. Based on this, the application of the eco-scale and the Green Certificate to the evaluation of these methodologies allows the method to be moved from the B and C classes to the A class.
Kinetic, isotherm and thermodynamic studies of the adsorption of methylene blue dye onto agro-based cellulosic materials
AbstractThe purpose of this work is to establish the optimal experimental conditions for the removal of methylene blue (MB-as model basic dye) from aqueous solution by adsorption onto four agro-based materials, namely, cedar sawdust, pine sawdust, wheat straw, and Provence cane Arundo donax. Results show that an increase in acidity or ionic strength of the medium has generally a negative effect on the discoloration yield. From the data of pH effect, there is no need to change the initial pH of the MB solution to be treated. Equilibrium was reached after 20−30 min of agitation when cedar sawdust, pine sawdust, and Provence cane are used as adsorbents. However, in the case of wheat straw, an …
Study of passive sampling of polycyclic aromatic hydrocarbons in gas phase using Amberlite XAD resins as filling materials of semipermeable membranes
Abstract In this work, a study was performed to evaluate the use of Amberlite XAD resins (XAD-2, XAD-4 and XAD-16), for the first time, as filling materials for low-density polyethylene membranes, which will be inserted as passive samplers for polycyclic aromatic hydrocarbons (PAHs) in gas phase. The use of samplers deployed for 48 h evidenced a relative capability to retain the compounds under study. A detailed study was performed to evaluate the recovery of analytes from the sampler through microwave-assisted extraction by using acetonitrile. A clean-up step using alumina-C18 cartridges was necessary before determination of the PAHs by high performance liquid chromatography with fluoresce…
Determination of tea tree oil terpenes by headspace gas chromatography mass spectrometry
An alternative procedure was developed for determining quality control of terpenes in tea tree oil commercial samples. The method is based on static headspace gas chromatography mass spectrometry measurements. Absolute limits of detection ranged from 1 ng for p-cymene to 71 ng for terpinen-4-ol. The accuracy of the developed methodology was evaluated by comparing the obtained eucalyptol and terpinen-4-ol concentrations with those provided for a certified sample and by comparing the developed procedure with literature tea tree oil analysis methodology. In the same way, spiked commercial samples provided recovery values ranging between 94% and 100% for all the target analytes with relative st…
Indoor and outdoor determination of pesticides in air by ion mobility spectrometry.
Abstract The use of ion mobility spectrometry (IMS) has been evaluated as analytical methodology to detect and evaluate the occupational exposure to pesticides. The developed IMS methodology was used, in positive and negative modes, to determine the presence of pesticides in air and to evaluate possible inhalation exposures of workers and users based on active sampling on Teflon membranes and direct thermal desorption IMS. The negative IMS mode was used to determine bensulfuron, clorpyrifos, diniconazole, diuron, flutolanil and imidacloprid, while the positive mode was employed to evaluate formetanate, metalaxyl, metamitrone, metribuzin, paclobutrazol and pirimicarb. The IMS measurements pr…
Date-rape evidence through fast determination of γ-butyrolactone in adulterated beverages.
Abstract An infrared spectroscopy (IR) based methodology has been developed to determine γ-butyrolactone (GBL) in adulterated beverages. The proposed method permits the direct screening of GBL in beverages and involves a minimum sample treatment requiring less than 2 min for quantitative determination of GBL. Sensitivity of IR method was improved by using liquid-liquid extraction (LLE) providing detection limits of 0.023 mg g−1. Accuracy of the proposed methodology was evaluated through the analysis of soft beverages and alcoholic cocktails spiked with GBL at concentration levels ranging from 0.075 to 10 mg g−1 providing recovery values from 91 to 100%. GBL was determined in twelve blind-sp…