Aqueous Reactions of Sulfate Radical-Anions with Nitrophenols in Atmospheric Context

Nitrophenols, hazardous environmental pollutants, react promptly with atmospheric oxidants such as hydroxyl or nitrate radicals. This work aimed to estimate how fast nitrophenols are removed from the atmosphere by the aqueous-phase reactions with sulfate radical-anions. The reversed-rates method was applied to determine the relative rate constants for reactions of 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, and 2,4,6-trinitrophenol with sulfate radical-anions generated by the autoxidation of sodium sulfite catalyzed by iron(III) cations at ~298 K. The constants determined were: 9.08 × 108, 1.72 × 109, 6.60 × 108, 2.86 × 108, and 7.10 × 107 M−1 s−1, respectively. These values correlated linearly with the sums of Brown substituent coefficients and with the relative strength of the O–H bond of the respective nitrophenols. Rough estimation showed that the gas-phase reactions of 2-nitrophenol with hydroxyl or nitrate radicals dominated over the aqueous-phase reaction with sulfate radical-anions in deliquescent aerosol and haze water. In clouds, rains, and haze water, the aqueous-phase reaction of 2-nitrophenol with sulfate radical-anions dominated, provided the concentration of the radical-anions was not smaller than that of the hydroxyl or nitrate radicals. The results presented may be also interesting for designers of advanced oxidation processes for the removal of nitrophenol

Green Leaf Volatiles in the Atmosphere—Properties, Transformation, and Significance

This review thoroughly covers the research on green leaf volatiles (GLV) in the context of atmospheric chemistry. It briefly takes on the GLV sources, in-plant synthesis, and emission inventory data. The discussion of properties includes GLV solubility in aqueous systems, Henry’s constants, partition coefficients, and UV spectra. The mechanisms of gas-phase reactions of GLV with OH, NO3, and Cl radicals, and O3 are explained and accompanied by a catalog of products identified experimentally. The rate constants of gas-phase reactions are collected in tables with brief descriptions of corresponding experiments. A similar presentation covers the aqueous-phase reactions of GLV. The review of multiphase and heterogeneous transformations of GLV covers the smog-chamber experiments, products identified therein, along with their yields and the yields of secondary organic aerosols (SOA) formed, if any. The components of ambient SOA linked to GLV are briefly presented. This review recognized GLV as atmospheric trace compounds that reside primarily in the gas phase but did not exclude their transformation in atmospheric waters. GLV have a proven potential to be a source of SOA with a global burden of 0.6 to 1 Tg yr−1 (estimated jointly for (Z)-hexen-1-ol, (Z)-3-hexenal, and 2-methyl-3-buten-2-ol), 0.03 Tg yr−1 from switch grass cultivation for biofuels, and 0.05 Tg yr−1 from grass mowing

Newly Discovered Components of Dendrolimus pini Sex Pheromone

The pine-tree lappet moth, D. pini, is a harmful defoliator of pine forests in Europe and Asia and a potentially invasive species in North America. The lures for trapping D. pini males based on two known components of its sex pheromone appeared weakly attractive to male moths. Identification of all components of the sex pheromone might allow for the development of more effective lures. The pheromone was sampled from virgin females using SPME and analyzed using gas chromatography coupled with mass spectrometry. Four new likely components ((Z5)-dodecenal, (Z5)-dodecen-1-ol, (Z5)-decen-1-yl acetate, (Z5)-tetradecen-1-yl acetate) and two known components ((Z5,E7)-dodecadienal, (Z5,E7)-dodecadien-1-ol) were identified based on comparison against authentic standards, Kováts indices and spectra libraries. The samples also contained several sesquiterpenes. Wind tunnel and field experiments showed that some blends of synthetic pheromone components alone or enriched with Scots pine essential oil (SPEO) were attractive to D. pini males. One component—(Z5)-decen-1-yl acetate—had a repelling effect. The presented knowledge of D. pini sex pheromone provides a basis for developing optimal lures for monitoring or controlling insect populations

Innovative aspects of dog training in high explosives detection

Psi nos jest nieocenioną pomocą dla ludzkości dzięki jego znakomitej czułości i zdolności do rozpoznawania oraz rozróżniania zapachów, tj. substancji lotnych wydzielanych przez dany materiał. W zestawieniu z coraz bardziej zaawansowaną technologią urządzeń elektronicznych do detekcji nadal zajmuje pierwsze miejsce na „podium”. Dzięki takim zdolnościom pies jest świetnym wsparciem w walce z terroryzmem, gdzie wczesne wykrycie materiałów wybuchowych (MW) odgrywa kluczową rolę dla bezpieczeństwa. W szkoleniu psów do wykrywania materiałów wybuchowych w polskich służbach mundurowych wykorzystuje się rzeczywiste próbki materiałów wybuchowych. Badania na arenie międzynarodowej wykazały jednak, że takie podejście nie daje stuprocentowej gwarancji wykrycia MW przez psa. Dodatkowo stosowanie klasycznych próbek MW w szkoleniu jest obarczone zarówno ryzykiem związanym z bezpieczeństwem przewodnika oraz psa, jak i z prawnymi restrykcjami podczas przechowywania, używania i transportu. Innowacyjne rozwiązanie wypracowane podczas realizacji tematu „Referencyjny zestaw próbek materiałów wybuchowych do szkolenia i atestacji psów służbowych” pozwala na większą swobodę manipulacji próbką szkoleniową, zwiększa bezpieczeństwo użytkowania i w rzeczywistości daje większą gwarancję wykrycia materiału wybuchowego przez psa.A nose of a dog is an invaluable help to humanity thanks to its excellent sensitivity and ability to recognize and distinguish odours, i.e. volatile substances emitted by a given material. In comparison with the increasingly advanced technology of electronic detection devices, it still ranks first on the “podium”. Due to its special abilities the dog is a great support in the fight against terrorism, where the early detection of explosives plays a key role in security. In the training process of a dog for the detection of explosives in Polish uniformed services genuine explosives samples are used. However, international studies have shown that this approach does not give 100% guarantee of HE detection by a dog. In addition, the use of classic HE samples in training involves a risk associated to the safety of both the operator and the dog and is burdened by law enforcement restrictions related to storage, use and transportation. An innovative solution developed during the implementation of the subject “Reference set of explosives samples for training and validation of service dogs” allows for more flexibility while handling the sample, increases the safety of use and provides a better detection of the explosive by the dog