Separation and determination of resibufogenin and cinobufagin in Chansu using reversed-phase liquid chromatography with γ-cyclodextrin as mobile-phase modifier

2012 ◽  
Vol 35 (15) ◽  
pp. 1884-1892 ◽  
Author(s):  
Jianfeng Xing ◽  
Lina Chen ◽  
Jie Song ◽  
Chenning Guo ◽  
Guangde Yang ◽  
...  
1996 ◽  
Vol 79 (4) ◽  
pp. 941-948
Author(s):  
James E Conaway ◽  
J B Audino ◽  
E Bane ◽  
S K Carrigan ◽  
R Glinsky ◽  
...  

Abstract A reversed-phase liquid chromatographic (LC) method for methomyl was studied. Twelve collaborators analyzed 3 solid and 4 liquid formulations on both a Zorbax octadecylsilane (ODS) column and a similar column of their choice. Methomyl and the internal standard were separated by using a mobile phase consisting of approximately 8% acetonitrile in water, which was monitored at 254 nm. The coefficient of variation on the Zorbax column ranged from 0.70 to 5.23%, while the range on the collaborators' house columns was 1.08 to 6.01%. Results with the Zorbax ODS column fell within the 5% 2-tail limits, and 10 of 11 collaborators' results fell within these limits on house columns. The LC method for determination of methomyl in insecticidal formulations has been adopted first action by AOAC INTERNATIONAL.


1991 ◽  
Vol 37 (12) ◽  
pp. 2117-2120 ◽  
Author(s):  
Lucile Gerbaut

Abstract A simple and rapid semiautomated procedure for determining polyamines in erythrocytes by high-performance liquid chromatography is described. Putrescine, spermidine, and spermine are converted to fluorescent dansyl derivatives, extracted with cyclohexane, and separated in <10 min on a reversed-phase C18 ODS column, with an acetonitrile-water gradient as the mobile phase. The method showed a coefficient of variation of 2.73% for spermidine and 3.27% for spermine. The respective reference values, evaluated in 10 healthy patients, were 7.88 (SD 2.09) and 5.42 (SD 1.55) μmol/L of packed erythrocytes. Only negligible amounts of putrescine were found.


1998 ◽  
Vol 81 (5) ◽  
pp. 1023-1026 ◽  
Author(s):  
Mohamed Tawfic Ahmed ◽  
Saad M M Ismail ◽  
Yahia Y Mosleh

Abstract A method for determining malathion residues by reversed- phase liquid chromatography (LC) using methanol only as mobile phase is described. Malathion [diethyl(dimethoxyphosphinothiol)succinate] was applied on marjoram, mint, and chamomile. Residues were detected in fresh and dry crops by LC and confirmed by gas-LC/mass spectrometry. Average recovery of malathion was 85%. Residues detected in fresh marjoram, mint, and chamomile were 0.18, 0.23, and 0.083 mg/kg, respectively. Residues detected in dry marjoram and mint were 0.024 and 0.050 mg/kg, respectively. No malathion residues were detected in dry chamomile. The minimum detectable concentration with this method is 0.013 mg/kg. The study suggests it is safe to use malathion up to 2 sprays per season provided the crop is harvested not less than 3 weeks from the last spray


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