PMID- 16772678
OWN - NLM
STAT- MEDLINE
DCOM- 20070524
LR  - 20190827
IS  - 0910-6340 (Print)
IS  - 0910-6340 (Linking)
VI  - 22
IP  - 6
DP  - 2006 Jun
TI  - Resonance Rayleigh-scattering method for the determination of sildenafil citrate 
      in a pharmaceutical formulation using Evans blue.
PG  - 819-23
AB  - A highly sensitive resonance Rayleigh-scattering (RRS) method for the 
      determination of sildenafil citrate has been developed, based on the fact that 
      sildenafil (Sild) reacted with Evans Blue (EB) to form an ion-association complex 
      in pH 1.1 - 4.6 aqueous solution. This resulted in a significant enhancement of 
      the RRS intensity, and a new spectrum appeared. The wavelength of the maximum RRS 
      was at 365 nm, and other scattering peaks were at 400, 442, 470 and 534 nm, 
      respectively. The intensity of RRS was directly proportional to the concentration 
      of Sild in the range 0 - 11.5 microg ml(-1), and the detection limit for Sild (3 
      sigma) was 30.3 ng ml(-1). The composition of the ion-association complex was 
      Sild:EB = 1:1, as established by Job's method. The method had good selectivity 
      and could be applied to the determination of Sild in the aqueous phase without 
      using organic solvent extraction. The method was simple and rapid. In addition, 
      the reaction mechanism and the reason for RRS enhancement were considered.
FAU - Liu, Shao-Pu
AU  - Liu SP
AD  - School of Chemistry and Chemical Engineering, Southwest China Normal University, 
      Chongqing, P. R. China. liusp@swnu.edu.cn
FAU - Fan, Li
AU  - Fan L
FAU - Hu, Xiao-Li
AU  - Hu XL
FAU - Liu, Zhong-Fang
AU  - Liu ZF
FAU - Li, Shan
AU  - Li S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Switzerland
TA  - Anal Sci
JT  - Analytical sciences : the international journal of the Japan Society for 
      Analytical Chemistry
JID - 8511078
RN  - 0 (Coloring Agents)
RN  - 0 (Pharmaceutical Preparations)
RN  - 0 (Piperazines)
RN  - 0 (Purines)
RN  - 0 (Sulfones)
RN  - 0 (Tablets)
RN  - 45PG892GO1 (Evans Blue)
RN  - BW9B0ZE037 (Sildenafil Citrate)
SB  - IM
MH  - Chemistry Techniques, Analytical/methods
MH  - Chemistry, Pharmaceutical/methods
MH  - Coloring Agents/*pharmacology
MH  - Evans Blue/*pharmacology
MH  - Hydrogen-Ion Concentration
MH  - Models, Chemical
MH  - Pharmaceutical Preparations/*chemistry
MH  - Piperazines/*analysis/chemistry
MH  - Purines/analysis/chemistry
MH  - Scattering, Radiation
MH  - Sildenafil Citrate
MH  - Spectrometry, Fluorescence/methods
MH  - Sulfones/*analysis/chemistry
MH  - Tablets
EDAT- 2006/06/15 09:00
MHDA- 2007/05/26 09:00
CRDT- 2006/06/15 09:00
PHST- 2006/06/15 09:00 [pubmed]
PHST- 2007/05/26 09:00 [medline]
PHST- 2006/06/15 09:00 [entrez]
AID - JST.JSTAGE/analsci/22.819 [pii]
AID - 10.2116/analsci.22.819 [doi]
PST - ppublish
SO  - Anal Sci. 2006 Jun;22(6):819-23. doi: 10.2116/analsci.22.819.