Simultaneous Kinetic Spectrophotometric Determination of Hydrazine and Isoniazid Using H-Point Standard Addition Method and Partial Least Squares Regression in Micellar Media

摘要

Opisano je simultano kinetičko spektrofotometrijsko određivanje hidrazina (HZ) i izonijazida (INH) upotrebom metode standardnog dodatka HPSAM (engl. H-Point Standard Addition Method) i regresijom parcijalnih najmanjih kvadrata (PLS, engl. Partial Least Squares). Metode se temelje na razlici u brzini redukcije željeza (III) s HZ odnosno INH u prisutnosti 2,2'-bipiridina (Bpy) i nastajanja kompleksa rezultirajućeg Fe~(2+) s Bpy u otopini natrije-vog dodecil sulfata kao micelarnom mediju. Spojevi se mogu odrediti istovremeno u rasponu masenih koncentracija od 0,08 μgmL~(-1) do 6,0 μg mL~(-1) za HZ i od 1,0 μg mL~(-1) do 80,0 μg mL~(-1) za INH. Rezultati su pokazali da se primjenom metode HPSAM istovremeno mogu odrediti oba spoja zastupljena u omjeru INH:HZ od 1:1000 do 1:12,5. Relativna standardna devijacija određivanja HZ metodom HPSAM bila je 2,5; a INH 1,2. Ukupna relativna standardna pogreška pri određivanju HZ (raspon koncentracija od 0,0 μg mL~(-1) do 20,0 μg mL~(-1)) i INH (raspon koncentracija od 0,5 μg mL~(-1) do 3,0 μg mL~(-1)) u 9 sintetičkih uzoraka metodom PLS bila je 3,19. Obje predložene metode (PLS i HPSAM) uspješno su primijenjene za simultano određivanje HZ i INH u nekoliko komercijalno dostupnih formulacija izonijazida.%The present study describes the application of simultaneous kinetic spectrophotometric determination of hydrazine (HZ) and isoniazid (INH), using H-point standard addition method (HPSAM) and partial least squares (PLS) calibration. The methods are based on the difference observed in the rate of iron (III) reduction with HZ and INH, in the presence of 2,2'-bipyridine (Bpy) and the subsequent complex formation between the resulted Fe~(2+) and Bpy in a solution containing sodium dodecyl sulfate (SDS) as a micellar medium. INH and HZ can simultaneously be determined between the range of 0.08-6.0 and 1.0-80.0 μg mL~(-1), respectively. The results have shown that by the application of HPSAM, the simultaneous determination could be performed with the ratio of 1:1000 to 1:12.5 for INH-HZ. Through the HPSAM analysis, the relative standard deviations of HZ and INH were 2.5 and 1.2, respectively. The total relative standard error for applying the PLS method to 9 synthetic samples, in the concentration ranges of 0.0-20.0 μg mL~(-1) of HZ and 0.5-3.0 μg mL~(-1) of INH, was 3.19. Both proposed methods (PLS and HPSAM) were successfully applied to the simultaneous determination of HZ and INH in several commercially available isoniazid formulations and satisfactory results were obtained.