Quantification of the influence of NO2, NO and CO gases on the determination of formaldehyde and acetaldehyde using the DNPH method as applied to polluted environments

Airborne aldehydes have a significant impact on human health, especially in confined spaces such as tunnels, vehicle depots, industrial and construction sites where combustion devices are in operation. The standard method for the measurement of aldehydes (formaldehyde and acetaldehyde) uses the 2,4-dinitrophenylhydrazine (DNPH) derivatisation method. However this method has been reported to be prone to interference from ozone and NO2. The interference from these compounds have been viewed as chromatographic interferences on the quantification of formaldehyde. However, in these polluted environments, elevated levels of NO2 along with NO and CO are normally present. This study quantifies the impact these gases have on the quantification of formaldehyde and acetaldehyde, by evaluating the chromatographic interferences, consumption of the DNPH during sampling, and the effect these gases have on the capture and retention of the aldehydes on the DNPH cartridge during sampling. For the first time, CO was shown to react with DNPH and interfere with the determination of acetone. The reaction product of CO with DNPH was determined to be a compound that could be mistaken for acetone-DNPH. It has been found that the presence of NO, NO2 and CO in the sampled air consumes the DNPH cartridges, which results in the loss of formaldehyde and acetaldehyde during long-term sampling, and therefore extra capacity of DNPH is required for the measurement of formaldehyde and acetaldehyde in polluted environments. These findings reveal a potential risk of underestimation of formaldehyde and acetaldehyde measurements in a polluted workspaces such as a diesel engine operated environment where NOx and CO concentration levels could be high

Gas-phase basicities of polyfunctional molecules. Part 2 : saturated basic sites

International audienc

Ending a patient’s life in the Polish criminal law

Przedmiotem artykułu jest omówienie regulacji eutanazji oraz medycznie wspomaganego samobójstwa w polskim prawie karnym. Postawiona zostaje teza, że stosowane obecnie regulacje: zabójstwa z litości (art. 150 K.k.) oraz pomocy w samobójstwie (art. 151 K.k.) nie uwzględniają kontekstu medycznego oraz sytuacji zdrowotnej ofiary, stąd prowadzone w literaturze rozważania dotyczące wysokości zagrożenia karnego oraz instytucji nadzwyczajnego złagodzenia kary są nieuzasadnione. Pominięte zostało rozważenie dopuszczalności wymienionych procedur medycznych, bowiem niezależnie od założeń aksjologicznych przyszła regulacja pozwoli na zwiększenie ochrony prawa do życia pacjentów oraz bezpieczeństwa prawnego personelu medycznego. Na zakończenie sformułowany zostaje zarys przyszłej regulacji.The subject of the article is a review of the regulation concerning a euthanasia and medically assisted suicide in the Polish criminal law. The thesis is that the currently applicable regulations on: mercy killing (article 150 of the Criminal Code) and assisted suicide (article 151 of CC) do not include the medical context nor the health situation of the victim, hence the discussion in the literature on the subject of the penalty and the institution of extraordinary mitigation of punishment is unjustified. The discussion on the admissibility of the above-mentioned medical procedures is omitted because regardless of its axiological basis, the future regulation will increase the protection of patients’ right to life and the legal security of medical staff. Finally, an outline of the future regulation is presented

Derivatization techniques for determination of carbonyls in air

"This review critically assesses the derivatization techniques employed in sampling and detection of carbonyl compounds in air. We explore the most common techniques reported for the collection of vapor-phase carbonyl compounds by focusing on the hydrazine-derivatization techniques developed with the aid of diverse sorptive media [solution (e.g., in impingers), solid sorbents, solid-phase extraction, solid-phase microextraction, and denuder, or other approaches]. We discuss the advantages and the disadvantages of each sampling and pretreatment option for key carbonyl compounds with reference to measurement data obtained under laboratory and field conditions. (C) 2014 Elsevier B.V. All rights reserved.&quot

Characterization of quality assurance properties of biogenic volatile organic compounds with an emphasis on the breakthrough behavior, recovery, and temporal stability

In this research, we investigated the breakthrough volume (BTV) and temporal performance of two types of sorbent tube (ST) sorbent beds toward 10 (target) biogenic volatile organic compounds (BVOCs) ((1) isoprene, (2) (+)-alpha-pinene, (3) camphene, (4) (+)-beta-pinene, (5) (+)-3-carene, (6) alpha-phellandrene, (7) alpha-terpinene, (8) (R)-(+)-limonene, (9) gamma-terpinene, and (10) p-cymene) and two (reference) anthropogenic volatile organic compounds (AVOCs) ((11) benzene and (12) toluene). The analysis of their vaporized liquid-phase working standards was carried out using thermal desorption-gas chromatography-mass spectrometry (TD-GC/MS). To this end, the performance of two ST types (CC (Carbopack C) and CBX (Carbopack C, Carbopack B, and Carbopack X)) was tested as a function of a few key variables, e.g., sorbent type, N-2 gas purge volume, and sampling temperature. The CBX ST gave recoveries of 100 +/- 10% at 60 degrees C for two BVOCs (camphene and alpha-terpinene). However, three compounds (isoprene, (+)-alpha-pinene, and (+)-beta-pinene) showed poor recoveries (0.7,59.3, and 11.3%,respectively), whilst p-cymene recorded an excess recovery (similar to 190%). In contrast, for the CC ST, BT for (+)-alpha-pinene and camphene increased with purge volume, while isoprene was not detected. Accordingly, the range of BTV5% and BTV50% values (L/g) for each compound with CC ST were 1.7 (toluene)-17 (camphene) and 15 (toluene) -570 ((+)-alpha-pinene), respectively. In summary, a three-bed CBX with the higher BTV is the preferred choice for environmental sampling for a wide range of BVOCs compared to a one-bed CC ST. The recovery of CBX ST for 10 out of 12 analytes (after ��150 reconditioning/loading/TD cycles) remained constant in terms of response factor, while the response factors of isoprene and beta-pinene were highly variable. Both the present work and the reported literature recoveries showed similar and divergent results which are discussed in terms of high temperature on-sorbent reactions. (C) 2015 Elsevier B.V. All rights reserved.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant No. 2013-004624). This work was also carried out with the support of the "Cooperative Research Program for Agriculture Science & Technology Development (Project title: Study on model development to control odor from pigpen, Project No. PJ01052101)" Rural Development Administration, Republic of Korea. The fourth author also acknowledges support made by a National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIP) (No. 2914RA1A004893)