Usporedba sadržaja cinka u različitim uzorcima inzulina plamenom atomskom apsorpcijskom spektroskopijom

master's thesis

• Title (english): Comparison of zinc content in various samples of insulin by flame atomic absorption spectroscopy
• Author: Tea Širac
• Mentor: Jasna Jablan (mentor)
• Committee member: Jasna Jablan (predsjednik povjerenstva)
• Committee member: Suzana Inić (član povjerenstva)
• Committee member: Živka Juričić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of analytical chemistry); Zagreb
• Defense date and country: 2019-05-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Cink ima važnu ulogu u svim fazama metabolizma inzulina, od proizvodnje preko lučenja i iskorištavanja do skladištenja.
Interakcija cinka i inzulina može dovesti do konformacijskih promjena i pojačati afinitet vezanja za receptore. Cink ima inzulinomimetičku aktivnost koja je najvjerojatnije posljedica inhibicije proteinskih tirozin fosfataza. On je i kofaktor enzima ključnih za metabolizam glukoze. Cilj ovog rada bio je validirati metodu određivanja cinka u inzulinu AAS-om i usporediti koncentraciju cinka u dva komercijalno dostupna pripravka inzulina u Republici Hrvatskoj. Sadržaj cinka u uzorcima određen je pomoću plamene apsorpcijske spektroskopije. Parametri validacije pokazali su zadovaljajuću linearnost u ispitivanom području (R2 =0,999). Ponovljivost metode, izražena kao relativna standardna devijacija (RSD) bila je između 0,5 % – 1,64 %, reproducibilnost metode između 3,1 % - 5,2 %, a dobivena točnost u rasponu između 95,6 % i 100,1 %. Granica dokazivanja bila je 0,025 mg/L, a granica određivanja 0,076 mg/L što pokazuje da je metoda pouzdana i osjetljiva za određivanje koncentracije cinka u uzorcima inzulina. Koncentracija cinka u komercijalno pribavljenim uzorcima inzulina bila je u rasponu od 0,152mg/L do 0191mg/L. Veći sadržaj cinka dobiven je u brzodjelujućemanalogu inzulina za razliku od sadržaja cinka kod bifazične suspenzije (30% brzodjelujući inzulin i 70%
srednjedugo djelujućeg humanog inzulina) gdje je bio nešto niži. Dobiveni rezultati potvrđuju činjenicu da je cink jedan od
parametara koji pospješuje brže vezanje inzulina na receptor te određuje duljinu djelovanja inzulina.

Abstract (english)

Zinc plays a significant role in all phases of insulin metabolism, from production through digestion and exploitation to storage. The interaction of zinc and insulin can lead to conformational changes and enhance binding affinity for receptors. Zinc possesses an insulin-mimetic activity that is most likely due to inhibition of protein tyrosine phosphatase. It is a cofactor of crucial enzymes for glucose metabolism. The aim of this research work was to validate the AAS method for determining zinc in insulin samples and to compare a concentration of zinc in two commercially available insulins in Croatia. The concentration of zinc in insulin samples was determined by flame atomic absorption spectroscopy. Validation parameters showed satisfactory linearity in the examined area (R2 = 0.999). The repeatability of the method expressed as the relative standard deviation (RSD) was between 0.5% - 1.64%, the reproducibility of the method was between 3.1% - 5.2%, the accuracy ranging between 95.6% and 100.1 %. The detection limit was 0.025 mg / L, and the determination limit was 0.076 mg / L. That shows the method is reliable and sensitive to determining the concentration of zinc in insulin samples. The concentration of zinc in commercially available insulin samples ranged from 0.152mg / L to 0191mg / L. The higher zinc content was obtained in the fast-acting insulin analog as opposed to the zinc content of the biphasic suspension (30% fast-acting insulin and 70% of the intermediate-acting human insulin) where it was little lower.

• Keywords: cink; inzulin; atomska apsorpcijska spektrofotometrija; validacija analitičke metode
• Keywords (english): zinc; insulin; atomic absorption spectroscopy; validation
• Language: croatian
• URN:NBN: urn:nbn:hr:163:582747
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-02-24 08:58:47