Determination of mass spectrometric sensitivity of different metalloporphyrin esters relative to porphyrin ester

Quantitative determination of metalloporphyrin contamination in preparations of biologically important porphyrins was achieved mass spectrometrically by application of the integrated ion current technique. For this purpose, the relative molecular ion sensitivities of the contaminating metal complexes were determined from the ratios of the integrated molecular ion currents of a series of calibration samples containing a porphyrin ester and one of its metal complexes in known molar ratio. Complexes formed with divalent ions of Cu, Zn, Fe, Co and Ni of copro- as well as uro-porphyrin permethylester were all found to have the same molecular ion sensitivities as their metal-free porphyrin ester. The relative metalloporphyrin ester content in a sample of porphyrin ester was thus obtained directly as the integrated ion current ratios of the normalized molecular ions. The preparation of calibration samples, including complex formation and the mass spectrometric methodology, is described and discussed.

Mucociliary function of the eustachian tube: assessment by saccharin test in patients with dry perforations of the tympanic membrane

The mucociliary function of the Eustachian tube was assess in 44 patients with dry perforations of the lympanic membrane by means of the saccharin test. A saccharin crystal was placed on the mucous membrane of the middle ear as close to the orifice of the Eustachian tube as possible, and the time taken for the patient to taste the saccharin was measured. The function of the Eustachian tube was also assessed by means of the aspiration test and by the Valsalva maneuver. No relationship was found between the results of the saccharin test, aspiration test, and the Valsalva maneuver. However, a correlation seems to exist between the hearing improvement obtained as determined by the postoperative air-bone gap, the positive or negative results of the saccharin test, and (in cases with positive saccharin test) the saccharin perception time.

Integrating Radiometer: A Self-Contained Device for Measurement of Submarine Light Energy in Absolute Units

The design, construction, and use of a self-contained submarine radiometer is described. The instrument measures the time-integral of the downwelling irradiance at a given depth in absolute units. The measurement error at 20 m in turbid coastal water is less than 5%. The instrument is useful in primary production and heat budget studies, and could rind many applications in terrestrial ecology.