Novel Polymeric Membrane Sensors Based on Mn(III) Porphyrin and Co(II) Phthalocyanine Ionophores for Batch and Flow Injection Determination of Azide
✍ Scribed by Saad S. M. Hassan; Ali E. Kelany; Saeed S. Al-Mehrezi
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 186 KB
- Volume
- 20
- Category
- Article
- ISSN
- 1040-0397
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✦ Synopsis
Abstract
Two novel potentiometric azide membrane sensors based on the use of manganese(III)porphyrin [Mn(III)P] and cobalt(II)phthalocyanine [Co(II)Pc] ionophores dispersed in plasticized poly(vinyl chloride) PVC matrix membranes are described. Under batch mode of operation, [Mn(III)P] and [Co(II)Pc] based membrane sensors display near‐ and sub‐Nernstian responses of −56.3 and −48.5 mV decade^−1^ over the concentration ranges 1.0×10^−2^−2.2×10^−5^ and 1.0×10^−2^−5.1×10^−5^ mol L^−1^ azide and detection limits of 1.5×10^−5^ and 2.5×10^−5^ mol L^−1^, respectively. Incorporation of both membrane sensors in flow‐through tubular cell offers sensitive detectors for flow injection (FIA) determination of azide. The intrinsic characteristics of the [Mn(III)P] and [Co(II)Pc] based detectors in a low dispersion manifold show calibration slopes of −51.2 and −33.5 mV decade^−1^ for the concentration ranges of 1.0×10^−5^−1.0×10^−2^ and 1.0×10^−4^−1.0×10^−2^ mol L^−1^ azide and the detection limits are1.0×10^−5^ and 3.1×10^−5^ mol L^−1^, respectively. The detectors are used for determining azide at an input rate of 40–60 samples per hour. The responses of the sensors are stable within ±0.9 mV for at least 8 weeks and are pH independent in the range of 3.9−6.5. No interferences are caused by most common anions normally associated with azide ion.