Publication: Cisplatin o-fenilendiamin kompleksinin oluşum koşullarının incelenmesi ve oluşan kompleks yardımıyla idrarda spektrofotometrik yöntemle cisplatin miktar tayini
Abstract
Cisplatin (CDDP), dozun iyi ayarlanamaması durumunda ciddi toksik etkileri olabilen, yaygın kullanımlı, antitümöral bir ilaç etken maddesidir. Kişiye göre doz ayarlaması ve nefrotoksisitesinin önlenmesi açısından kan ve idrarda izlenmesi önemlidir. Moleküler spektrofotometrik tayin yönünden ele alındığında molar sönüm katsayısı düşüktür. Tayinin duyarlığını arttırmak için bir türevlendirme reaksiyonuna gerek duyulmaktadır. Bu çalışmada cisplatinin o-fenilendiamin (OPDA) ile verdiği ürünün optimum oluşum koşulları; çözücü, sıcaklık, pH, reaksiyon süresi, reaktif ve klorür iyonu konsantrasyonu açısından incelenmiş ve oluşturulmuş olan bu tayin yöntemi, idrara uyarlanmıştır. Cisplatin ile OPDA'nın verdiği reaksiyon ürününün maksimum absorpsiyonu; OPDA'nın, idrardaki bileşiklerin ve cisplatinin absorpsiyon verdiği dalga boyu aralığından oldukça uzak olan 705 nm de gözlenmektedir. Yüksek klorür konsantrasyonlarında reaksiyonun baskılanmasına rağmen, reaktifin yüksek konsantrasyonlarda kullanılmasıyla bu dezavantajın ve idrardan ileri gelen diğer girişimlerin üstesinden gelinmiştir. Mavi - yeşil renkli ürünün oluşumu pH @ 6,20 de, 1,0.10-5 M klorür çözeltisinde, cisplatin konsantrasyonunun 60 katı konsantrasyonda, 90 oC'de 30 dakikada tamamlanmaktadır. İdrarda ve 1,5.10-1 M klorür çözeltisinde, aynı koşullarda, 600 katı konsantrasyonda OPDA kullanılarak reaksiyon gerçekleştirilmiştir. Bu şekilde klorür girişiminin ve idrardan ileri gelen girişimlerin de üstesinden gelinmiştir. Yukarıda belirlenen her iki koşulda da aynı konsantrasyon için absorbans değerleri değişmediğinden oluşan ürünün molar sönüm katsayısı yaklaşık olarak 91 000 L mol-1 cm-1 dir. 1,0.10-5 M klorür çözeltisinde gerçekleştirilen reaksiyon sonucu konsantrasyon ve absorbans arasında 0,30 - 3,00 mg mL-1 aralığında, idrarda ise 0,42 - 3,58 mg mL-1 aralığında doğrusallık bulunmuştur. Bu durumda bu yöntemin idrarda tayin sınırı 8,40 mg mL-1 olmaktadır. Standart katma yöntemiyle 8,40 mg mL-1, 16,8 mg mL-1 ve 28,0 mg mL-1 konsantrasyonlarda cisplatin katılmış olan idrarlarda % 76,19, % 76,19 ve % 78,61 i bulunmuştur. İdrarda sisplatin tayini için geliştirilmiş olan bu yöntem, ön işleme gerek duyulmadan, idrarda basit bir türevlendirme reaksiyonu sonucu elde edilen mavi-yeşil rengin görünür bölge spektroskopisi yardımıyla doğrudan tayinine dayanan kolay ve ucuz bir yöntemdir. Ayrıca yüksek klorür konsantrasyonlarında bile değişmeden kalan cisplatin tayinine olanak vermektedir. INVESTIGATION OF THE FORMATION CONDITIONS OF CISPLATINUM - o-PHENYLENEDIAMINE COMPLEX AND THE DETERMINATION OF CISPLATIN THROUGH THIS COMPLEX
Cisplatin (CDDP) is an antitumoral drug with a wide therapeutical use, that may have serious toxicity when the dose is not regulated properly. CDDP monitoring in urine has an importance in regulating dosage and investigating its nephrotoxicity. Its molar extinction coefficient is quite low when the optical detection is sought. Therefore a derivatizing reaction is required to provide the sensitivity of its detection. In this study, the optimum formation conditions of cisplatinum / o-phenylenediamine complex was determined in terms of the effect of the solvent, temperature, pH, reaction time, reactant and chloride ion concentration and the method that is developed in aqueous medium was applied and modified to urine medium. The maximum absorption of the reaction product of cisplatin and OPDA is at 705 nm, which is far beyond the wavelengths of the absorption of cisplatin itself, o-phenylenediamine and the biomolecules in urine. Although the reaction was inhibited in high chloride ion concentrations, this disadvantage and the other interferences from urine matrix were overcome by using the high concentration of the reactant. The formation of the blue - green product was completed at 90 oC in 30 minutes in the presence of o-phenylenediamine in the concentration of 60 times of CDDP concentration in 1,0.10-5 M chloride ion and 600 times of CDDP concentration in 1,5.10-1 M chloride ion at pH @ 6,20. Its extinction coefficient was found approximately about 91 000 L mol-1 cm-1 in above conditions. A linear relationship was found between concentration and absorbance in 0,30 - 3,00 mg mL-1 concentration range in about 1,0.10-5 M chloride ion. The quantification method developed, was finally applied to urine and the linearity between concentration and absorbance was found in 0,42 - 3,58 mg mL-1 concentration range. The determination limit of cisplatin in urine with this method was 8,40 mg mL-1 and the percentages of spiked cisplatin detected by this method were 76,19 %, 76,19 %, 78,61 % in 8,40 mg mL-1, 16,8 mg mL-1 and 28,0 mg mL-1 CDDP spiked urines, in order. This method, developed for the determination of cisplatin in urine, allows an easy and a very cheap quantification of the blue-green product obtained by a simple derivatization in urine, through visible spectrophotometry without any sample pretreatment. It is also possible to determine the intact CDDP selectively in high chloride concentrations by this method.
Cisplatin (CDDP) is an antitumoral drug with a wide therapeutical use, that may have serious toxicity when the dose is not regulated properly. CDDP monitoring in urine has an importance in regulating dosage and investigating its nephrotoxicity. Its molar extinction coefficient is quite low when the optical detection is sought. Therefore a derivatizing reaction is required to provide the sensitivity of its detection. In this study, the optimum formation conditions of cisplatinum / o-phenylenediamine complex was determined in terms of the effect of the solvent, temperature, pH, reaction time, reactant and chloride ion concentration and the method that is developed in aqueous medium was applied and modified to urine medium. The maximum absorption of the reaction product of cisplatin and OPDA is at 705 nm, which is far beyond the wavelengths of the absorption of cisplatin itself, o-phenylenediamine and the biomolecules in urine. Although the reaction was inhibited in high chloride ion concentrations, this disadvantage and the other interferences from urine matrix were overcome by using the high concentration of the reactant. The formation of the blue - green product was completed at 90 oC in 30 minutes in the presence of o-phenylenediamine in the concentration of 60 times of CDDP concentration in 1,0.10-5 M chloride ion and 600 times of CDDP concentration in 1,5.10-1 M chloride ion at pH @ 6,20. Its extinction coefficient was found approximately about 91 000 L mol-1 cm-1 in above conditions. A linear relationship was found between concentration and absorbance in 0,30 - 3,00 mg mL-1 concentration range in about 1,0.10-5 M chloride ion. The quantification method developed, was finally applied to urine and the linearity between concentration and absorbance was found in 0,42 - 3,58 mg mL-1 concentration range. The determination limit of cisplatin in urine with this method was 8,40 mg mL-1 and the percentages of spiked cisplatin detected by this method were 76,19 %, 76,19 %, 78,61 % in 8,40 mg mL-1, 16,8 mg mL-1 and 28,0 mg mL-1 CDDP spiked urines, in order. This method, developed for the determination of cisplatin in urine, allows an easy and a very cheap quantification of the blue-green product obtained by a simple derivatization in urine, through visible spectrophotometry without any sample pretreatment. It is also possible to determine the intact CDDP selectively in high chloride concentrations by this method.