Fluorometric Determination of Nadolol in Human Serum and Urine

1977 ◽  
Vol 66 (8) ◽  
pp. 1168-1172 ◽  
Author(s):  
Eugene Ivashkiv
Keyword(s):  
Human Serum ◽  
Fluorometric Determination ◽  
Serum And Urine

A highly selective colorimetric assay for the determination of creatinine in biological samples using gluconic acid capped silver nanoparticles after ionic liquid based dispersive liquid phase microextraction

2021 ◽  
pp. 1-8
Author(s):  
Susan Sadeghi ◽  
Mohadeseh Hosseinpour-Zaryabi
Keyword(s):  
Silver Nanoparticles ◽  
Ionic Liquid ◽  
Liquid Phase ◽  
Human Serum ◽  
Gluconic Acid ◽  
Ag Nps ◽  
Liquid Phase Microextraction ◽  
Relative Standard ◽  
Serum And Urine

A dispersive liquid-phase microextraction method combined with UV–vis spectrophotometry was utilized to highly selective determination of creatinine in human serum and urine samples. To overcome the interferences in complex matrices, creatinine reacted with 1,4-naphthoquinone-2- potassium sulfonate reagent to produce a red coloured product that could be extracted into a small volume of 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM]PF6) ionic liquid solvent. To increase the sensitivity of the assay, gluconic acid capped silver nanoparticles (Ag NPs) were used. On addition of Ag NPs to the red coloured extracted product, the solution turned to blue accompanied with a red shift in wavelength around 620 nm that could be detected by the naked eye. The effective variables on the determination of creatinine such as concentration of the reagent, amount of formic and hydrochloric acids, type and volume of the extractant, and concentration of Ag NPs were investigated. Under the optimal conditions, the calibration plot was bimodal with linear ranges from 0.1 to 1.5 µg mL−1 and 1.5 to 105 µg mL−1 creatinine with a limit of detection 0.1 µg mL−1. The relative standard deviation for five measurements at 35 µg mL−1 concentration level was 3.8%. The newly developed assay was used for the determination of creatinine in human serum and urine specimens with satisfactory results.

scholarly journals Determination of Picogram Levels of Roxithromycin in Pharmaceutical, Human Serum, and Urine by Flow-Injection Chemiluminescence

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Jiangman Liu ◽  
Huan Yang ◽  
Yun Zhang ◽  
Min Wu ◽  
Haixiang Zhao ◽  
...  
Keyword(s):  
Human Serum ◽  
Flow Injection ◽  
Limit Of Detection ◽  
Inhibitory Effect ◽  
Injection System ◽  
Relative Standard ◽  
Flow Injection System ◽  
Flow Injection Chemiluminescence ◽  
Serum And Urine

A sensitive chemiluminescence (CL) method, based on the inhibitory effect of roxithromycin (ROX) on the CL reaction between luminol and dissolved oxygen in a flow-injection system, was first proposed for the determination of ROX at picogram levels. The decrement of CL intensity was linearly proportional to the logarithm of ROX concentrations ranging from 0.1 to 100 pg mL-1, giving the limit of detection (LOD) of 0.03 pg mL-1 (3σ). At a flow rate of 2.0 mL min-1, a complete analytical procedure including sampling and washing could be performed within 0.5 min, with relative standard deviations (RSDs) of less than 5.0% (n=5). The proposed procedure was applied successfully to the determination of ROX in pharmaceutical, human serum, and urine with the recoveries ranging from 90.0 to 110.0%.

Isopropylidine maltoheptosyl fructofuranoside, doubly blocked substrate for determination of endoamylase activity

1991 ◽  
Vol 37 (8) ◽  
pp. 1323-1328
Author(s):  
Z Ogawa ◽  
Y Matsubayashi ◽  
S Satoh ◽  
N Orita ◽  
H Itoh
Keyword(s):  
Human Serum ◽  
Coefficient Of Variation ◽  
Oxidation Rate ◽  
Amylase Activity ◽  
Mannitol Dehydrogenase ◽  
Coupled Reactions ◽  
Alpha Glucosidase ◽  
Serum And Urine

Abstract We synthesized o-(4,6-o-isopropylidene-alpha-D-glucopyranosyl)-(1----4)- [o-alpha-D-glucopyranosyl-(1----4])5-o-alpha-D-glucopyranosyl-(1----2)- alpha-D-fructofuranoside (IPG7F) and developed an assay for determining the activity of amylase in human serum and urine by using this substrate. Glucoamylase, alpha-glucosidase, and mannitol dehydrogenase are used as coupling enzymes. The coupled reactions are monitored by continuously measuring the oxidation rate of NADH. In this procedure, various substances in the test specimens do not interfere with the detection of amylase activity. Exactly one molecule of NADH is oxidized by one attack of amylase on the substrate, although four products can be produced in the reaction. The within-assay coefficient of variation (CV) ranged from 1.0% to 4.1% and the between-assay CV ranged from 2.6% to 5.3%. The results of our new assay correlate well with those of the amylase assay involving p-nitrophenol maltoheptaoside as substrate (r = 0.978) and with those of the amylase assay involving maltopentaose (r = 0.987).

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