Caption: Figure 4: (a) The
diphenylamine test data.
In addition to the pilot test to validate the technology in the field, the team evaluated the quantities of
diphenylamine, or DPA, present on a treated apple.
Five redox indicators (2,3'-diphenylamine dicar-boxylic acid, diphenylaminesulfonic acid,
diphenylamine, iodine:starch, and luminol) were evaluated against hydrogen peroxide and potassium chlorate.
An improved
diphenylamine method for the estimation of deoxyribonucleic acid.
Most early propellant powders were stabilized with
diphenylamine or ethyl centralite.
160 [micro]l of freshly prepared
diphenylamine (150mg
diphenylamine in 10ml glacial acetic, 150[micro]l concentrated [H.sub.2]S[O.sub.4] and 50[micro]l of acetaldehyde solution) was added and the tubes were allowed to stand overnight at room temperature to develop colour.
That finding, in turn, has led to 1-MCP's use as an alternative to preventing apple scald with
diphenylamine, a chemical antioxidant that requires close monitoring.
Treating apples with the chemical antioxidant
diphenylamine can prevent scald, but the practice can be complicated and requires careful monitoring.
In the past, colorimetric or fluorometric assays used reagents such as
diphenylamine, which when added to the patient's plasma/serum produced a color change, the degree of which correlated with the DNA concentration (57-59).
Nitrate in plant tissue can also be sampled by a simple test using
diphenylamine. The
diphenylamine reacts with N[O.sub.3.sup.-] in plant tissue to form a blue color, the intensity of which varies with the amount of N[O.sub.3.sup.-] present.
Some of the more common stabilizers used to extend the safe life of the energetics are
diphenylamine, methyl centralite, and ethyl centralite.
In the non-organic apples, tests found 0.13mg/kg of the fungicide
diphenylamine. The legal maximum residue level (MRL) limit set by the Pesticides Safety Directorate (PSD) for this chemical is 5mg/kg, so the traces found are negligible.