Benchtop 19F NMR spectroscopy as a practical tool for testing of remedial technologies for the degradation of perfluorooctanoic acid,a persistent organic pollutant

The development of effective remedial technologies for the destruction of environmental pollutants requires the ability to clearly monitor degradation processes. Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for understanding reaction progress; however, practical considerations often restrict the application of NMR spectroscopy as a tool to better understand the degradation of environmental pollutants. Chief among these restrictions is the limited access smaller environmental research labs and remediation companies have to suitable NMR facilities. Benchtop NMR spectroscopy is a low-cost and user-friendly approach to acquire much of the same information as conventional nuclear magnetic resonance (NMR) spectroscopy, albeit with reduced sensitivity and resolution. This paper explores the practical application of benchtop NMR spectroscopy to understand the degradation of perfluorooctanoic acid using sodium persulfate, a common reagent for the destruction of groundwater contaminants. It is found that Benchtop ¹⁹F NMR spectroscopy is able to monitor the complete degradation of perfluorooctanoic acid into fluoride; however, the observation of intermediate degradation products formed, which can be observed using a conventional NMR spectrometer, cannot be readily distinguished from the parent compound when measurements are performed using the benchtop instrument. Under certain reaction conditions, the formation of fluorinated structures that are resistant to further degradation is readily observed. Overall, it is shown that benchtop ¹⁹F NMR spectroscopy has potential as a quick and reliable tool to assist in the development of remedial technologies for the degradation of fluorinated contaminants.     

Supports of semi-stable probability measures on locally convex spaces

LetE be a locally convex space. Let be an absolutely convexly tight Radom semi-stable probability measure onE with index 1<2 and Lévy measureM. The main result of this paper shows that the closed semigroup generated by the support ofM and the negative of the barycenter ofM restricted to a suitable compact subset ofE is a (closed) linear space ofE, and that the support of is a suitable translate of this linear space. This result complements a few known results concerning the supports of stable and semi-stable probability measures. In particular, it extends an analogous result proved recently for the support of -stable probability measures 1<2 (Ref. 4). Related results concerning the support of Radon semi-stable probability measures onE of index 0<<1 are also discussed.The research of this author was partially supported by AFSOR Grant No. 90-0168The research of this author was supported by KBN Grant, and the University of Tennessee Science Alliance, a State of Tennessee Center of Excellence.     

On sample path properties of semistable processes

This paper contains three main results: In the first result a correspondence principle between semistable measures on L_p, 1 ≤ p < ∞, and Banach space valued semistable processes is established. In the second result it is shown that the paths of a Banach space valued semistable process belong to L_p with probability zero or one, and necessary and sufficient conditions for the two alternatives to hold are given. In the third result necessary and sufficient conditions are given for almost sure path absolute continuity for certain Banach space valued semistable processes.     

Uniform Comparison of Tails of (Non-Symmetric) Probability Measures and Their Symmetrized Counterparts with Applications

Let (, ) be a separable Banach space and let be a class of probability measures on , and let denote the symmetrization of . We provide two sufficient conditions (one in terms of certain quantiles and the other in terms of certain moments of relative to μ and , ) for the “uniform comparison” of the μ and measure of the complements of the closed balls of centered at zero, for every . As a corollary to these “tail comparison inequalities,” we show that three classical results (the Lévy-type Inequalities, the Kwapień-Contraction Inequality, and a part of the It?–Nisio Theorem) that are valid for the symmetric (but not for the general non-symmetric) independent -valued random vectors do indeed hold for the independent random vectors whose laws belong to any which satisfies one of the two noted conditions and which is closed under convolution. We further point out that these three results (respectively, the tail comparison inequalities) are valid for the centered log-concave, as well as, for the strictly α-stable (or the more general strictly (r, α) -semistable) α ≠ 1 random vectors (respectively, probability measures). We also present several examples which we believe form a valuable part of the paper.      

Synthesis of O-Alkylbenzohydroximoyl Iodides and a Comparison of their Structures to other Oxime Derivatives

Abstract  The first general synthesis of (Z)-O-alkylbenzohydroximidoyl iodides [ArC(I)=NOR] is reported. X-ray crystallographic structures of two of these compounds confirm that they are in the Z-configuration: p-NO₂ArC(I)=NOCH₃ crystallizes in space group Pnma with lattice constants a = 12.682(2) ?, b = 6.5217(15) ?, and c = 11.755(2) ?, and p-ClArC(I)=NOCH₃ crystallizes in space group P2₁/n with lattice constants a = 15.670(4) ?, b = 5.742(4) ?, and c = 27.156(7) ? and beta angle 102.71(2). Their structures are compared to other O-alkylbenzohydroximoyl halides including p-NO₂ArC(F)=NOCH₃ which crystallizes in space group P2₁/c with lattice constants a = 3.8475(10) ?, b = 22.501(5) ?, and c = 10.088(2) ? and beta angle 91.130(11). The synthesis of two additional compounds containing the N-alkoxyimine moiety {methyl (Z)-O-methyl-4-nitrobenzothiohydroximate [p-NO₂ArC(SCH₃)=NOCH₃] which crystallizes in space group P2₁/n with lattice constants a = 11.8046(15) ?, b = 7.0774(10) ?, and c = 12.2741(15) ? and beta angle 100.401(9) and (Z)-O-methyl-4-nitrobenzohydroximoyl azide [p-NO₂ArC(N₃)=NOCH₃] which crystallizes in space group P2₁/c with lattice constants a = 11.753(2) ?, b = 11.310(3) ?, and c = 7.351(2) ? and beta angle 103.805(15) are also reported. Their structures are compared to (Z)-ethyl benzohydroximate [PhC(OEt)=NOH] and (Z)-O-methyl-4-nitrobenzohydroximoyl cyanide [p-NO₂ArC(CN)=NOCH₃] respectively. Characterizations include spectrometric identifications employing IR, ¹H-NMR, ¹³C-NMR and mass spectrometry. Index Abstract  X-ray structures of several N-alkoxyimines, including the newly synthesized N-alkoxyimidoyl iodides and azide, have been performed, and these structures unambiguously show the geometric configuration (E vs. Z) of these compounds.

Regeneration-Based Quantification of Coumarins (Scopoletin and Scoparone) in <Emphasis Type="Italic">Abutilon indicum</Emphasis> In Vitro Cultures

Abutilon indicum exploited for its immense value has been propagated successfully through multiple shoot induction and somatic embryogenesis. Direct regeneration (8.20?±?0.83 shoots) was achieved from nodal explants using 0.5 mg/l kinetin (Kn) in MS media. The basal callus from nodal explants turned embryogenic on subsequent introduction of 0.2 mg/l TDZ into the Kn-supplemented media, giving rise to somatic embryos. The embryogenic potential of calli expressed in terms of embryo-forming capacity (EFC) increased from 8.15 EFC to 20.95 EFC after plasmolysis. The phytochemical analysis (HPLC) for the presence of scopoletin and scoparone has revealed a unique accumulation pattern, with higher levels of scopoletin during the earlier stages and scoparone in the later stages of development. The embryogenic calli contained the highest amount of coumarins (99.20?±?0.97 and 61.03?±?0.47 μg/gFW, respectively) followed by regenerated plant (9.43?±?0.20 and 36.36?±?1.19 μg/gFW, respectively), obtained via somatic embryogenesis. Rapid multiplication of A. indicum equipped with two potent coumarins is important in order to meet the commercial demand for combat against dreadful diseases, thereby providing a new platform for plant-based drugs and their manufacture on a commercial scale.