Nitrate interference with potassium-selective microelectrodes

Cuin, TA; Miller, AJ; Laurie, SA; Leigh, RA

HERO ID

4829070

Reference Type

Journal Article

Year

1999

HERO ID 4829070
In Press No
Year 1999
Title Nitrate interference with potassium-selective microelectrodes
Authors Cuin, TA; Miller, AJ; Laurie, SA; Leigh, RA
Journal Journal of Experimental Botany
Volume 50
Issue 340
Page Numbers 1709-1712
Abstract Initial attempts to measure K+ activity (a(k)) in vacuoles of barley leaf epidermal cells using triple-barrelled K+-Selective microelectrodes gave values that were only about one-third of those expected. This was due to high (c. 200 mM) NO3- concentrations in the vacuoles interfering with the K+-sensor, The effect of NO3- was on 1,2,-dimethyl-3-nitrobenzene (DNB) used as a plasticizer in the K+-sensor. Replacing DNB with dibutyl sebacate, but not with 2-nitrophenyl octyl ether, overcame this problem and the modified sensor gave acceptable calibration curves with no interference from physiological concentrations of other ions, These electrodes were used successfully to measure a mean a(k) of 235 mM in vacuoles of epidermal cells of K+-replete barley leaves.
Doi 10.1093/jexbot/50.340.1709
Wosid WOS:000083652400011
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword leaf epidermis; potassium activity; potassium-selective microelectrodes; vacuoles; nitrate interference
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