Although the Winkler method is very precise when performed with strict control of pH and iodine concentration, it is still susceptible to errors. For example, ions such as Fe2+ and SO3-, suspended solids, and some organics can produce gross inaccuracies. There have been numerous modifications of the method over the years to compensate for its shortcomings (2). Besides the errors inherent in the...

ii Abstract (in Finnish) iiiin Finnish) iii

Although the Winkler method is very precise when performed with strict control of pH and iodine concentration, it is still susceptible to errors. For example, ions such as Fe2+ and SO3-, suspended solids, and some organics can produce gross inaccuracies. There have been numerous modifications of the method over the years to compensate for its shortcomings (2). Besides the errors inherent in the...

A novel amperometric sensor that integrates two independent measurement schemes into a single chip for detection of glucose is fabricated. The sensor uses micro-patterned Prussian blue (PB) and ferrocene modified glucose oxidase covered by a thin Nafion membrane. We have developed an amperometric sensor for the detection of glucose that integrates two measurement schemes into a single chip. For...

Neurotransmitters and hormones are stored within secretory vesicles inside the cell and release their contents in a quantal event by fusion with the plasma membrane. We develop and fabricate microchip devices that we apply in cell experiments for electrochemical measurements of quantal release events from adrenal chromaffin cells. Surface patterned electrodes on transparent surfaces are applied...

The paper presents the using of amperometric sensors in measurements of the oxygen content in the organic solutions such as beer. The resulted data compared with spectrophotometric data.