The chemicals contained in this kit may be hazardous if
improperly handled. Read the relevant Health and Safety
Data Sheet before performing this test.
HEALTH AND SAFETY
HEALTH AND SAFETY
HEALTH AND SAFETY
HEALTH AND SAFETY
HEALTH AND SAFETY
R E F E R E N C E S
R E F E R E N C E S
R E F E R E N C E S
R E F E R E N C E S
R E F E R E N C E S
P.Sequi,
Chimica del suolo
, Patron editore, Ed. 1991
Interferences
• Compounds with buffering capacity (substances that
keep the pH of sample at a constant value, e.g.
phosphate buffer, ammonia buffer): if after Mannitol
reagent has been added pH of sample does not change,
verify if pH increases a little (0.05 pH units) by adding
HI 38074E-0 reagent drop by drop. In this case boron
may be present, but a buffer interferes with boron
determination. It is possible to have only an indication
for boron concentration. Use the Boron Conversion Table
below to convert the number of drops added in mg/L
(or ppm) of Boron and record the concentration of boron
in your sample as lower than the value found (e.g.: 2
drops correspond to 0.4 mg/L of Boron, thus boron
concentration in your sample is lower than 0.4 mg/L).
• Bicarbonates: if hardness of sample is about 150 ppm
CaCO
3
, bicarbonates are present at pH 8.3, and they
interfere with boron determination. In this case the
sample needs to be pretreated before analysis as de-
scribed in the following paragraph.
Pretreatment to eliminate carbonate interference
• Fill the plastic vessel with 50 mL of sample and pour it
into the empty bottle.
• Add HI 38074B-0 reagent until pH is lower than 4.5.
Place the cap, but DO NOT SCREW IT.
• Heat the sample for about 45 seconds in a microwave
oven at 500W (do not boil the sample). Swirl several
times to eliminate air bubbles and allow the sample to
cool down to room temperature. Pour the sample into
the plastic vessel and perform the test as described
above.
