Determination of "true" serum creatinine by high-performance liquid chromatography combined with a continuous-flow microanalyzer.

1977 ◽  
Vol 23 (7) ◽  
pp. 1281-1283 ◽  
Author(s):  
N D Brown ◽  
H C Sing ◽  
W E Neeley ◽  
S E Koetitz

Abstract We coupled a high-performance liquid chromatograph with a continuous-flow microanalyzer to produce a system for specifically determinig "true" creatinine in urine and serum specimens. A selective microbore pellicular cation-exchange column and a single eluting sodium citrate buffer are used to separate the noncreatinine but Jaffé-positive constituents from the creatinine in normal and experimental specimens. The effluent is analyzed continuously, on-line, the alkaline picrate complex being developed and measured in the microanalyzer. Physiological samples, reference standards, and internal control specimens are assayed in 6-min intervals subsequent to the initial injection. The relationship between concentration and peak are is linear for creatinine standards between 5 and 10 mg/liter. Specimen volumes ranging from 1 to 25 microliters, and containing creatinine in amounts exceeding 5 ng per injected sample, can be assayed with this system.

1990 ◽  
Vol 73 (4) ◽  
pp. 627-631
Author(s):  
Edgar C Nicolas ◽  
Kathleen A Pfender ◽  
Michael A Aoun ◽  
Jane E Hemmer

Abstract A fast and simple method for determination of taurine in Infant formulas has been developed. The sample preparation uses disposable ultrafiltration cartridges to remove protein and clarify the sample. Hydrolysis Is avoided, simplifying the procedure and increasing efficiency. One mL sample Is centrlfuged In a cartridge for 45 mln. The filtrate Is diluted with pH 2.2 citrate buffer and Injected into a high performance amino acid analyzer. A cation-exchange column (sodium phase) Is used with a single buffer eluant and an Isocratic chromatographic program. Colorimetrlc detection is performed following post-column nlnhydrln reaction. Chromatographic resolution from other nlnhydrln-posltive compounds is excellent. Average recoveries for 3 levels of spike for various products were 100-102%. Precision Is 1-3% RSD, depending on product. Linearity, specificity, and ruggedness are excellent. The method Is applicable to quality control testing of milk-based, soy-based, and prehydrolyzed proteinbased Infant formulas In the ready-to-use, concentrate, and powder forms. A variety of commercially available Infant formulas from different manufacturers were analyzed and all were found to contain taurine levels comparable to human milk. Some human milk and cow's milk samples were also analyzed and results compare well with literature values


2018 ◽  
Vol 69 (3) ◽  
pp. 627-631 ◽  
Author(s):  
Viorica Ohriac (Popa) ◽  
Diana Cimpoesu ◽  
Adrian Florin Spac ◽  
Paul Nedelea ◽  
Voichita Lazureanu ◽  
...  

Pain is defined as a disagreeable sensory and emotional experience related to a tissue or potential lesion. Paracetamol (Acetaminophen) is the most used non-morphine analgesic. For the determination of paracetamol we developed and validated the high performance liquid chromatography (HPLC) analysis using a Dionex Ultimate 3000 liquid chromatograph equipped with a multidimensional detector. After determining the optimum conditions of analysis (80/20 water / acetonitrile mobile phase, flow rate 1.0 mL / min, detection wavelength 245 nm) we validated the method following the following parameters: linearity of response function, linearity of results, limit (LD = 0.66 mg / mL) and quantification limit (LQ = 2.00 mg / mL), and precision. The method of determining paracetamol by HPLC was applied to 30 samples of serum collected from patients who had pain and were treated with paracetamol.


Author(s):  
Klaudia Kokoszka ◽  
Agnieszka Kobus ◽  
Sylwia Bajkacz

The residues of antimicrobials used in human and veterinary medicine are popular pollutants of anthropogenic origin. The main sources of introducing antimicrobials into the environment are sewage treatment plants and the agricultural industry. Antimicrobials in animal manure contaminate the surrounding soil as well as groundwater, and can be absorbed by plants. The presence of antimicrobials in food of plant origin may pose a threat to human health due to their high biological activity. As part of the research, a procedure was developed for the extraction and determination of ciprofloxacin, enrofloxacin, cefuroxime, nalidixic acid and metronidazole in environmental samples (soil and parsley root). An optimized solid-liquid extraction (SLE) method was used to separate antimicrobials from the solid samples and a mixture of citrate buffer (pH = 4): methanol (1:1; v/v) was used as the extraction solvent. Solid phase extraction (SPE) with OASIS® HLB cartridges was used to purify and pre-concentrate the sample. The recovery of the developed method was in the range of 55–108%. Analytes were determined by high-performance liquid chromatography coupled with an ultraviolet (UV) detector and a tandem mass spectrometer (HPLC-UV-MS/MS). The procedure was validated and applied to the determination of selected antimicrobials in soil and parsley root samples. Five types of soil and five types of parsley roots of different origins were analyzed. The presence of nalidixic acid in the parsley root samples was found in the concentration range of 0.14–0.72 ng g−1. It has been shown that antimicrobials are absorbed by the plant and can accumulate antimicrobials in its edible parts.


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