Hg. Taber et R. Killorn, DETERMINATION OF NITRATE IN UNFILTERED EXTRACTS OF MUSKMELON TISSUE BY ION-SELECTIVE ELECTRODES, Communications in soil science and plant analysis, 24(11-12), 1993, pp. 1231-1241
Nitrate (NO3-N) determination with ion-selective electrodes (ISE) on m
uskmelon (Cucumis melo L.) leaf petiole tissue was equivalent to the c
admium (Cd) reduction method provided that the aluminum sulfate [Al2(S
O4)3] buffer solution was >0.04M to eliminate ionic strength effects f
rom varying NO3 and chloride (Cl) concentrations. Recovery of added NO
3 was better with the HACH ISE, 98.8%, as compared with Orion ISE, 93.
6%. The addition of silver sulfate (Ag2SO4) did not significantly impr
ove NO3 recovery with either ISE. The addition of carbon depressed the
detected NO3 concentration by 9.7%. The HACH ISE offers the advantage
of a inexpensive, easy-to-use, single body electrode with a durable m
embrane allowing the filtration step to be eliminated.