[Show abstract][Hide abstract] ABSTRACT: The comparison method of fingerprints of the lacquer coat of cars (LCC) was established by using thermal desorption instrument with gas chromatography. The actual LCC samples were also analyzed. The samples were cut out to proper size and placed in the desorption furnace of the thermal desorption instrument. The volatile organic compounds in LCC were desorbed from the lacquer coat samples in the furnace under the chosen temperature, then separated in the capillary column and detected on a flame ionization detector of gas chromatography. The incipient judgment whether the two fingerprints of LCC were the same can be made from the contour and figure of the chromatograms. To make farther study of the two similar fingerprints, the overlap ratio of the peaks and relative retention values were given in the article. The two LCC samples can be regarded as the same if the overlap ratio of peaks was more than 90%, and the similarity of the ratio of relative retention times r(t2) and r(t1) and relative peak areas r(A2) and r(A1) in the two fingerprints were more than 99% and 70%, respectively. The method is good in repeatability and is easily carried out. The peaks in the fingerprint can be readily recognized. The fingerprint was characterized quantitatively. The method can be used in the department of traffic police and the comparison result can be used as material evidence in the court.
No preview · Article · Dec 2005 · Se pu = Chinese journal of chromatography / Zhongguo hua xue hui
[Show abstract][Hide abstract] ABSTRACT: A sensitive and rapid method was developed for purity determination of different types of aprotinin by micellar electrokinetic capillary chromatography (MECC). MECC was performed with 80 mmol/L Na2HPO4-H3PO4(pH 7.00) buffer solution containing 4 mmol/L cetyltrimethyl ammonium bromide (CTAB) at an applied voltage of 15 kV. The electrophoresis was monitored at 277 nm, and completed in 6 minutes. The relative standard deviations of migration time and area for aprotinin were below 0.3% and below 5% respectively within 1 day (for 6 repetitive runs). The effect of high concentration of salt in the samples has been studied. The results obtained by capillary zone electrophoresis, MECC and high performance liquid chromatography were compared, and those of MECC were the best.
No preview · Article · Aug 2002 · Se pu = Chinese journal of chromatography / Zhongguo hua xue hui