Spectrophotometric Determination of Trace Quantities of Pure Atropine and Pharmaceutical Preparations with SbI4 2− Ion

This study aims to estimate a simple, rapid and sensitive method for a trace
amount of atropine (ATR) in medicinal compounds. Two approaches were followed to
accomplish this aim, i.e., spectrophotometric determination of pure ATR and
pharmaceutical preparations using SbI4
2− ion as a new reagent. The procedure involves
the implementation of an ion-association complex with this alkaloid. The resulting
complex was extracted and detected spectrophotometrically at 492 nm. Appropriate
parameters were investigated, including the ion SbI4
2− concentration and the pH value of
the complex formation. Using chloroform to extract the complex, taking into
consideration extraction time and volume of solvent used. The calibration graph is linear
in the ranges of 0.5–5.0 × 10−3 M. Precision, accuracy, detection limit, and RSD %, as well
as relative standard deviation (n = 5), were calculated. The test sensitivity was
0.013 μg cm−2. Several interference additives were studied by investigating the effect of
equal and duplicate quantities of some common excipients on selectivity, such as starch,
glucose, lactose, glycerin, and talc. The molar ratio of the SbI4
2−_ATR was determined.
The amount of ATR in the pharmaceutical tablets and eye drop preparation was
calculated using Erel at ratios of 2.24 and 2.75%, respectively.