Acidity electronic spectroscopy

Ascorbic acid Electronic spectroscopy Meniscus height changing Paracetamol solution Supersmall doses... 

Ab initio molecular orbital calculations were reported for methylenes CXY, methyli-dynes CX and for their anions, CXY- and CX-, where X and Y are all possible combinations of H, F and Cl325. Gas-phase acidities, electron affinities and heats of formation have been calculated325. CXY- anions (X = F, Cl, Br and I, Y = H) have also been studied by photoelectron spectroscopy and structures have been reported327. 

Hong et al. examined the effect of nitric acid passivation on type 430 ferritic stainless steel using potentiodynamic polarization, EIS, and Auger electron spectroscopy (AES) (18). Passivation treatments were carried out on wet polished surfaces by immersion for 60 minutes in nitric acid solutions ranging from 1 to 61% at 50°C. Pitting potential and the magnitude of the total impedance were positively correlated with surface Cr concentration. In response to this study,... 

One good example is provided by the carboxylic acids. It is generally believed, as in Taft s work, that the relative high acidity of these compounds originates from the truism that carboxylate ions are resonance stabilised . Siggel et al. suggested on the basis of Ol s electron spectroscopy and ab initio calculations that the high relative instability of the acid rather than the stability of the anion is the key factor [31,32]. On the other hand, more recent theoretical analysis has re-... 

Theories and instrumentation of Fourier transform IR spectroscopy and electron spectroscopy for chemical analysis are briefly reviewed. The possibility of using these techniques in detection and analysis of acid impurities distributed at surfaces of paper documents produced during the period from 1790 to 1983 is demonstrated. Results show that all of the papers tested contained carboxylic groups. The carboxylic acids found in the paper of 1790 are the results of oxidation and aging. Acids in other papers are due to fiber oxidation as well as the presence of rosin acids. These techniques show promise as nondestructive methods for elucidating chemical characteristics of surfaces of paper documents. 

The measurement of acidity in paper documents with cold- and hot-water extraction frequently distorts and damages the paper fibers and printing inks. Many paper conservators and museum curators have long desired a reliable and rapid method for the detection of acidity of paper documents in a nondestructive manner so that they can determine the acidity routinely to screen out valuable book documents for deacidification or other necessary preservation treatments. The objective of this chapter is to introduce two spectroscopic techniques, namely, Fourier transform IR spectroscopy (FTIR) and electron spectroscopy for chemical analysis (ESCA), for chemical analysis of paper surfaces. The effectiveness of these techniques in analyzing and determining the presence of acidic functional groups on paper documents is demonstrated. 

---