Comments to the Acidification and Bubbling Method for Determining Phytoplankton Production

The acidification and bubbling method, a liquid scintillation counting (LSC) technique could yield erroneous results if the effects of suspended phytoplankton organisms on 14C counting efficiency (physical quenching, selfabsorption) are disregarded. of pH change and incorporation of 14C by diatoms, blue-green and green algae on 14C counting efficiency were investigated. paper gives experimental evidence that the suggested LSC technique does not discriminate between dissolved and particulate 14C labelled compounds, and acidification does not interfere with 14C counting efficiency. Thus selfabsorption can be neglected and quenching does not need to be considered if 14C activity of each sample is measured twice, at its natural pH and after acidification and bubbling. The paper further demonstrates, that this technique provides highly reproducible results. in primary production research, the application of the acid bubbling method, a simple, relatively inexpensive and accurate technique, is highly recommended.