2.4. Statistical analysis
The results of all measurements were presented on a fresh
weight basis as mean ± standard deviation. Iodine measurements
by the spectrophotometric methodology and the ICP-MS methodology were compared by analysis of variance (ANOVA) and
the least significant difference method, with p < 0.05 being used to
indicate a statistically significant difference (SPSS version 13.0,
SPSS Inc. Chicago, IL, USA).
3. Results and discussion
3.1. Analytical quality control
Important parameters on method validation (accuracy, precision,
LOD, LOQ) are presented in Tables 1A and B. Based on the
results obtained from determination of iodine by spectrophotometric
and ICP-MS methods, the results were agreed well with
the certified values of the SRM and RM, which indicate good performance
of the two methods for iodine analyses. The per cent
recovery obtained by spectrophotometry (85–108%) and ICP-MS
(92–103%) were within the acceptable range (80–110%, AOAC,
2012). For analytical precision, HORRAT values were in the
accepted range of 0.3–1.3 (AOAC, 2012).