Reverse injection enthalpimetric technique for the determination of cerium (IV)‎ and sulpha drugs

Abstract EN

The new thermometric sensor developed by the present authors and appeared in (Talanta, 2007, 71(1),141-148) has been subjected to further applications.

In this work Ce (IV) has been determined using Reverse Injection Enthalpimetry (RIE) , in which the analyte Ce(IV) was added to excess reagent (sulphanilic acid).

For the determination of (4 - 35 μg.mL-1) Ce(IV) in the final solution, a fixed volume between (0.1–0.8) mL.

analyte present in.

(0.5 M H2SO4), was injected into an excess of sulphanilic acid (20 ml.

1.25 x 10-2M) in the thermometric cell.

Only one blank of 0.5 ml.(0.5 M H2SO4) was performed and its value was subtracted from all the results.

The calibration curve was linear with R2 = 0.999 with a recovery between 96– 101% with precision of about 2 %, and t-test showed no significant difference between the true value and the mean at 95 % confidence limit, indicating good validity of the method.

The above procedure was reversed for the determination of sulphanilic acid and some sulpha drugs.

In this case a portion of 0.5 mL.

of the analyte or the standard containing not less than 10mg of sulphanilic acid or the sulpha–drug is injected into an excess of Ce (IV) as a reagent in the thermometric cell and the procedure will be continued.