Determination of trace borohydride in basic solutions using differential pulse polarography

Ülkü ÜNAL and Güler SOMER

Makale detayları

Determination of trace borohydride in basic solutions using differential pulse polarography

Yazarlar:

Ülkü ÜNAL and Güler SOMER

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2009 Vol.33 Issue 5, pp.657-665

Belge Tipi:

Makale

Yayın Tarihi:

4/2009

Belge Dili:

Türkçe

Document ID (Org No.):

2000728223

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527

Özet:

 

Synthesis of borohydride is important because of its use as  a hydrogen energy source.  The objective of this study was to develop  a new and simple method for the trace determination of borohydride so  that it can be used during the investigation of a new reaction for its  synthesis or in some kinetic studies.  A differential pulse polarographic method has been developed for this  purpose since the results obtained with this method are very  reproducible and the instrument used is not expensive.  The optimum  working condition was found to be as 0.05 M phosphate buffer (pH 9),  containing 0.1 M KNO3 electrolyte.  It allows trace determination of  borohydride in the range of 10-4-10-6 M using the oxidation peak  at --0.06 V with high accuracy.  The detection limit was 6 \times  10-7 M in phosphate buffer.  The nature of the peak was evaluated  using direct current polarography and it was found that this peak at  --0.06 V was an oxidation peak.  There was no serious interference from some cations such as Cr(III),  Cr(VI), Fe(III), Cd(II), Pb(II), Zn(II), Ni(II), and Se(IV) and anions  such as chloride, bromide, nitrate, and sulfite when 2-14 times of  borohydride was present.  It was found that only copper (II) had an  overlapping peak.  This interference of copper was eliminated by the  addition of EDTA. Using this procedure, in the presence of 5 \times  10-5 M copper, for 2 \times 10-5 M borohydride the result found  was (1.9 \pm 0.2)10-5 M for N = 3 and 90% confidence interval.

 

Synthesis of borohydride is important because of its use as  a hydrogen energy source.  The objective of this study was to develop  a new and simple method for the trace determination of borohydride so  that it can be used during the investigation of a new reaction for its  synthesis or in some kinetic studies.  A differential pulse polarographic method has been developed for this  purpose since the results obtained with this method are very  reproducible and the instrument used is not expensive.  The optimum  working condition was found to be as 0.05 M phosphate buffer (pH 9),  containing 0.1 M KNO3 electrolyte.  It allows trace determination of  borohydride in the range of 10-4-10-6 M using the oxidation peak  at --0.06 V with high accuracy.  The detection limit was 6 \times  10-7 M in phosphate buffer.  The nature of the peak was evaluated  using direct current polarography and it was found that this peak at  --0.06 V was an oxidation peak.  There was no serious interference from some cations such as Cr(III),  Cr(VI), Fe(III), Cd(II), Pb(II), Zn(II), Ni(II), and Se(IV) and anions  such as chloride, bromide, nitrate, and sulfite when 2-14 times of  borohydride was present.  It was found that only copper (II) had an  overlapping peak.  This interference of copper was eliminated by the  addition of EDTA. Using this procedure, in the presence of 5 \times  10-5 M copper, for 2 \times 10-5 M borohydride the result found  was (1.9 \pm 0.2)10-5 M for N = 3 and 90% confidence interval.

Makale detayları

Determination of trace borohydride in basic solutions using differential pulse polarography

Yazarlar: Ülkü ÜNAL and Güler SOMER

Yayıncı: TUBITAK

Dergi: Turkish Journal of Chemistry 2009 Vol.33 Issue 5, pp.657-665

Belge Tipi: Makale

Yayın Tarihi: 4/2009

Belge Dili: Türkçe

Document ID (Org No.): 2000728223

Sıklık: İki Aylık

eISSN: 1303-6130

pISSN: 1300-0527

Sayı

Yazarlar:

Ülkü ÜNAL and Güler SOMER

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2009 Vol.33 Issue 5, pp.657-665

Belge Tipi:

Makale

Yayın Tarihi:

4/2009

Belge Dili:

Türkçe

Document ID (Org No.):

2000728223

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527