A lead-EDTA spectrophotometric methods for sulphate determination

A method for the detn. of sulfate in aq. solns. is based on the pptn. of Pb sulfate, which is then dissolved by an EDTA soln., and spectrophotometric detn. (l = 242 nm) of the Pb-EDTA complex. A H2O-MeOH mixt. is used as the solvent in order to decrease the soly. of the Pb sulfate, and Ba(II) is added to the soln. contg. excess EDTA in order to eliminate the EDTA interference. Sulfate concns. >5 mg/L can be detd. without preconcn. with a relative std. deviation <0.035; the scatter of absorbance measurements around the calibration line corresponds, on the av., to 0.4 mg/L, when 15 mL of sample are taken for anal

Technology, colours, forms, and shapes in the 2nd century glass opus sectile materials from the villa of Lucius Verus in Rome

Attribuzione di migliaia di lastre in vetro, monocromo e policromo, confluite nella collezione Gorga, alla villa dell'imperatore Lucio Vero (II secolo) sulla via Cassia, e studio delle tecniche di produzione

Bilateral trochlear nerve palsy associated with cryptococcal meningitis in human immunodeficiency virus infection

This is the report of a case of bilateral trochlear nerve palsy secondary to cryptococcal meningitis in a 34-year-old woman with acquired immune deficiency syndrome. Based on clinical and neuroradiologic findings, it is concluded that in the present case, a postinflammatory shrinking of the arachnoid has stretched the fourth cranial nerves at their point of emergence from the dorsal surface of the brainstem

Performance evaluation of mapping and linear imaging FTIR microspectroscopy for the characterization of paint cross sections

Different Fourier transform infrared microspectroscopic techniques, using attenuated total reflection (ATR) mode and single-element mercury–cadmium– telluride (MCT) detector (mapping) or multielement MCT detector (raster scanning), are compared with each other for the characterisation of inorganic compounds and organic substances in paint cross sections. All measurements have been performed on paint cross sections embedded in potassium bromide, a transparent salt in the mid-infrared region, in order to better identify the organic materials without the interference of the usual embedding resin. The limitations and advantages of the different techniques are presented in terms of spatial resolution, data quality and chemical information achieved. For all techniques, the chemical information obtained is found to be nearly identical. However, ATR mapping performed with a recently developed instrumentation shows the best results in terms of spectral quality and spatial resolution. In fact, thin organic layers (&#8764;10 &#956;m) have been not only identified but also accurately located. This paper also highlights the recent introduction of multielement detectors, which may represent a good compromise between mapping and imaging systems