Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 121 (2014) 288–291

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A novel chemiluminescence system with diperiodatonickelate (IV) for the determination of adrenaline Chunyan Yang a,⇑, Fubin Chen a, Ziqiang Chang a, Yonghua Sun b, Zhujun Zhang c a Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong, Sichuan 637002, China b Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Material and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, China c College of Chemistry and Materials Science, Shaanxi Normal University, Xi’an, Shaanxi 710062, China

h i g h l i g h t s

g r a p h i c a l a b s t r a c t

 A new chemiluminescence system

with diperiodatonickelate.  The possible CL emission mechanism

briefly discussed.  Successfully applied to the

determination of adrenaline in pharmaceutical preparations.

a r t i c l e

i n f o

Article history: Received 21 June 2013 Received in revised form 17 September 2013 Accepted 23 October 2013 Available online 1 November 2013 Keywords: Chemiluminescence Diperiodatonickelate Adrenaline

a b s t r a c t A novel chemiluminescence (CL) system with diperiodatonickelate (IV) (DPN) was developed for the determination of adrenaline for the first time. The possible CL emission mechanism was briefly discussed by comparing the fluorescence emission spectra with CL spectra. Under the optimum conditions, the relative CL intensity was linear over the concentration of AD ranging from 1.0  107 to 1.0  105 g mL1 with a detection limit of 4.0  108 g mL1 (3r). And the relative standard deviation was 3.7% for 2.0  106 g mL1 AD (n = 11). The developed method has been successfully applied to the determination of AD in pharmaceutical preparations. Ó 2013 Elsevier B.V. All rights reserved.

Introduction Adrenaline (4-[1-hydroxi-2-methylamine], AD) is an endogenous catecholamine drug biosynthesized in the adrenal medulla and sympathetic nerve terminals. Pharmaceutically, it is widely used in the treatment of neural disorders [1].

⇑ Corresponding author. Tel.: +86 817 2568081. E-mail address: [email protected] (C. Yang). 1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.10.094

A series of analytical methods were reported for the determination of AD, such as spectrophotometry [2–4], fluorescence [5–9], LC [10–13], electrochemistry [14–21] and CL [22–28]. CL is one of the most popular techniques for the analysis of pharmaceutical compounds because of its inherent analytical advantages, such as relatively simple and inexpensive instrumentation (no light source and monochromator required), low detection limits and wide linear working range. The goal of the present work was to develop a novel direct CL method coupled with flow-injection for the determination of AD in commercial pharmaceutical products. Some

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transition metals in highest oxidation states such as tetravalent nickel can be stabilized by chelating with suitable polydentate ligand which is a powerful oxidizing agent in alkaline medium. Mechanism of oxidation of some organic compounds by DPN has been performed [29–33]. To our knowledge, there is no report about the direct CL reaction of DPN. This work focuses on researching and developing a novel DPN CL reaction system for the determination of AD. The developed method has been successfully applied to the determination of AD in pharmaceutical preparations. The possible CL emission mechanism was briefly discussed.

Experimental Material AD was obtained from Drug and Biological Products Examination Bureau of China (http://www.nicpbp.org.cn/CL0001/) which was dissolved in water to make a stock solution at a concentration of 1.0  104 g mL1. Potassium persulfate (Shanghai Aijian Chemical Reagent Company, http://www.ajchem.com); potassium hydroxide, sodium nitrate, sodium periodate, nickel sulfate (Shanghai Chemical Reagent Research Institute, http://www.scrri. com/). All the reagents were of analytical grade. Deionized and doubled distilled water was used throughout. DPN was synthesized according to the procedure described previously [34]. The UV–vis absorption spectrum of DPN is shown in Fig. 1. The concentration of DPN solution was determined gravimetrically after reducing nickel (IV) to nickel (II) as the dimethyl glyoxime complex.

Fig. 2. Schematic diagram of the FI–CL system (a: AD standard solution or samples; b: distilled water; c: DPN solution; V: injection valve; F: spiral glass flow cell; PMT: photomultiplier; pump1, pump2: peristaltic pumps).

Analytical procedure As shown in Fig. 2, the distilled water which was propelled by pump delivered the AD or the sample solution in the sample loop to merge directly with DPN solution in the flow cell to emit CL. The CL signal was detected with IFFS-A multifunction chemiluminescence analyzer. The concentration of AD was quantified by the peak height of the CL signal.

Apparatus

Results and discussion

The CL–FIA system used in this work is shown in Fig. 2. Two peristaltic pumps (HL-2, Shanghai Huxi, China) were used to deliver all the chemicals. Polytetrafluoroethylene (PTFE) flow tubes (0.8 mm i.d.) were used to connect all the components in the flow system. 90 lL of sample solution was injected into the water stream by eight-way injection valve and then mixed with the reagent streams. The CL signal was monitored by IFFM-A multifunction chemiluminescence analyzer (Remex Analytical Instrument Co. Ltd., Xian, China). The UV absorbance was detected with the TU1901 UV–Vis spectrophotometer (Beijing Purkinje General Instrument Co., Ltd., China). The CL spectrum was monitored using F-4600 fluorescence spectrophotometer (Shimadzu, Japan).

Kinetic characteristics of CL reaction system Before the flow injection method was carried out, the kinetic characteristics of the developed CL reaction were studied by using the batch method. In the batch mode, the experimental parameters were kept constant. The typical response curve of AD reacted with DPN was recorded to study the kinetic characteristic of the CL reaction. Fig. 3 demonstrates that the CL reaction was very quick. The peak of the CL intensity appeared within 0.5 s since the AD solution was injected. Then the signal would decrease instantly to baseline within 0.8 s. So it is concluded that the length of the mixing tube of DPN and AD should be as short as possible in the flow injection method.

Fig. 1. The UV–vis absorption spectra of DPN.

Fig. 3. Kinetic characteristic of the CL reaction of DPN–AD–OH system (1 mL 5.0  104 mol L1 DPN in 0.1 mol L1 KOH, 0.1 mL 2.0  106 g mL1 AD).

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Optimization of the flow-injection CL system In order to evaluate the optimum operating condition of the flow system, the CL intensity of 8.0  107 g mL1 AD was measured with respect to the reaction variables. The flow rate is an important factor which influences the analytical sensitivity. The effect of the flow rate of two pumps on CL intensity was examined in the range of 0.5–3.5 mL min1. The results showed that the CL signal increased with the increasing of flow rate, because the CL reaction is rapid. So 3.5 mL min1 which was the maximal flow rate under present conditions was selected as optimum. The CL reaction was performed in alkaline condition. The alkalinity of reaction medium was adjusted by varying the concentration of KOH in DPN solution. The effect of KOH concentration on the CL intensity was examined in the range of 0.03–0.4 mol L1. As can be seen from Fig. 4A, the maximal CL intensity could be obtained when KOH concentration was 0.1 mol L1. DPN is the oxidant in the CL reaction. The influence of DPN concentration in the range of 5.0  105–8.0  104 mol L1 on the CL signal was tested. Fig. 4B shows the maximal CL signal could be obtained when the concentration of DPN was 4.0  104 mol L1. Analytical performance of the developed method Under the selected conditions given above, the calibration graph of relative CL intensity (DI) versus AD concentration (C)

was linear in the range 1.0  107–1.0  105 g mL1 with a detection limit of 4.0  108 g mL1 (3r). The linear regression equations is DI = 34.19C + 179.68 with correlation coefficient of 0.9902. The relative standard deviation was 3.7% for 2.0  106 g mL1 AD (n = 11). The developed method has been successfully applied to the determination of AD in pharmaceutical preparations. Interference studies The effect of foreign substances was tested by analyzing a standard solution of AD (2.0  106 g mL1) under the optimum experimental conditions mentioned above. The tolerable concentration of foreign species was taken as a relative error

A novel chemiluminescence system with diperiodatonickelate (IV) for the determination of adrenaline.

A novel chemiluminescence (CL) system with diperiodatonickelate (IV) (DPN) was developed for the determination of adrenaline for the first time. The p...
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