[Detection and determination of acetone using semiconductor sensors]. / Untersuchungen zum Nachweis und zur Bestimmung von Aceton mit Halbleitersensoren.

Investigations to examine not only the factors of influence on evaluation of acetone by self-prepared semiconductor gas sensors, but also to prove analytical properties, were carried out using different tools. A sensor temperature of 600 degrees C and a carrier gas flow-rate of 5 l/h were found to be suitable conditions for the measurement of flow-injection apparatus. The determination of 1 microliter-samples of aqueous solutions containing 1-700 g of acetone/l yielded deviations of 4 to 33%. Using a head space method, the working temperature of 370 degrees C led to a maximum sensor response, the detection limit ranged from 37.5 to 50 mg of acetone/l. After quantifying 5 microliters-sample solutions of 40-600 mg/l, results with an accuracy of 1 to 36% were obtained. The method showed the possibility of distinguishing concentrations of acetone below and above 40 mg/l according to physiological and pathological urinary values. The tests carried out on 100 human urine samples provide a good agreement with the Legal reference method for samples containing physiological or strong pathological amounts of ketone bodies, but not for those including traces and small amounts. False-positive results might be caused by a possible presence of ethanol in urine.

[Extraction behavior of polypropylenes. 87. Problems in the use of plastic containers for fluid drugs]. / Extraktionsverhalten von Polypropylen. 87. Mitteilung: Zur Problematik des Einsatzes von Kunststoffbehältern für flüssige Arzneizubereitungen.

Studies on the extraction of antioxidants in different polypropylene samples subjected to variable extraction terms proved that storing neutral or faintly acid infusion solutions or those with an ethanol content up to 10% for several months, the extracted antioxidants are in allowable ranges. Insignificantly increased amounts of antioxidants are delivered to alkaline solutions and to ethanol/water mixtures having increased ethanol contents. The methods and specified limiting values of the GDR pharmacopoeia have been consulted for the semiquantitative estimate of extractives.