Subzero-Temperature Liquid−Liquid Extraction of Benzodiazepines for High-Performance Liquid Chromatography

1999 ◽  
Vol 71 (9) ◽  
pp. 1918-1921 ◽  
Author(s):  
Manabu Yoshida ◽  
Atsushi Akane
2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Deepthika De Silva ◽  
Steven Lee ◽  
Anna Duke ◽  
Siva Angalakurthi ◽  
Ching-En Chou ◽  
...  

These studies represent the first report on the intravascular residence time determinations for the cyanide antidote dimethyl trisulfide (DMTS) in a rat model by using high performance liquid chromatography coupled with ultraviolet absorption spectroscopy (HPLC-UV). The newly developed sample preparation included liquid-liquid extraction by cyclohexanone. The calibration curves showed a linear response for DMTS concentrations between 0.010 and 0.30 mg/mL withR2= 0.9994. The limit of detection for DMTS via this extraction method was 0.010 mg/mL, and the limit of quantitation was 0.034 mg/mL. Thus this calibration curve provided a tool for determining DMTS in the range between 0.04 and 0.30 mg/mL. Rats were given 20 mg/kg DMTS dose (in 15% Polysorbate 80) intravenously, and blood samples were taken 15, 60, 90, 120, and 240 min after DMTS injections. The data points were plotted as DMTS concentration in RBCs versus time, and the intravascular residence time was determined graphically. The results indicated a half-life of 36 min in a rat model, suggesting that the circulation time is long enough to provide a reasonable time interval for cyanide antagonism.


2019 ◽  
Vol 6 (8) ◽  
pp. 190952 ◽  
Author(s):  
Nur Hidayah Sazali ◽  
Anas Alshishani ◽  
Bahruddin Saad ◽  
Ker Yin Chew ◽  
Moi Me Chong ◽  
...  

In this study, salting-out assisted liquid–liquid extraction (SALLE) as a simple and efficient extraction technique followed by high-performance liquid chromatography (HPLC) was employed for the determination of vitamin D3 in milk samples. The sample treatment is based on the use of water-miscible acetonitrile as the extractant and acetonitrile phase separation under high-salt conditions. Under the optimum conditions, acetonitrile and ammonium sulfate were used as the extraction solvent and salting-out agent, respectively. The vitamin D3 extract was separated using Hypersil ODS (250x i.d 4.6 mm, 5 µm) HPLC column that was coupled with diode array detector. Vitamin D2 was used as internal standard (IS) to offset any variations in chromatographic conditions. The vitamin D3 and the IS were eluted in 18 min. Good linearity ( r 2 > 0.99) was obtained within the range of 25–600 ng g −1 with the limit of detection of 15 ng g −1 and limit of quantification of 25 ng g −1 . The validated method was applied for the determination of vitamin D3 in milk samples. The recoveries for spiked samples were from 94.4 to 113.5%.


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