detection of amino acids on porous

detection of amino acids on porous surfaces than both ninhydrin
and DFO. The addition of metal salts to indanedione treated
amino acid spots was further able to increase the sensitivity of
detection. The results obtained in the sensitivity study of
conventional reagents were comparable to previously published
results [4,18]. The optimised 1,2-indanedione formulation was
more sensitive than results reported by Roux et al., when
glycine was detected using white light, however the same study
reported greater sensitivity for the luminescence detection
using 1,2-indanedione and metal salts [4].
1,2-Indanedione, ninhydrin and the metal salt complexes of
both reagents, were able to detect glycine down to a
concentration of 2.0  103 mg/mL using white light only.
The sensitivity of DFO was slightly less, detecting a
concentration of 3.9  103 mg/mL.
DFO and 1,2-indanedione were comparable in their ability
to detected glycine, using fluorescence, at a concentration of
2.4  104 mg/mL. The metal complexes of ninhydrin were
not as sensitive, detecting glycine at a lowest concentration of
4.9  104 mg/mL.
The addition of the metal salt solutions to the 1,2-
indanedione treated glycine caused a colour change, from a
pale pink colour to a dark pink. The metal salt treatment greatly
increased the sensitivity of the reagent, with both cadmium and
zinc metal salt complexes being able to detect glycine at
6.1  105 mg/mL (Table 2).