High-performance liquid chromatographic assay of (+/-)-lactic acid and its enantiomers in calf serum
ABSTRACT Two high-performance liquid chromatographic methods are described for the determination of lactic acid and its enantiomers in calf serum. A 300x8.0 mm I.D. column packed with sulfonated styrene-divinylbenzene copolymer and a 50x4.6 mm ODS column with N,N-dioctyl-L-alanine were used. UV detection was at 205 and 236 nm for the non-chiral and chiral assays, respectively. Both assays demonstrated excellent linear relationships between peak area ratios and serum concentrations over a range of 0.5 to 20 mM, based on 100 microl bovine serum. Recovery was complete. Inter- and within-batch bias and relative standard deviation were <15%.
- SourceAvailable from: Saman Abeysekara
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- "In healthy rabbits, mean serum d-lactate concentration determined by HPLC was 0·17 ±0·08 mmol/L. Results obtained with HPLC on five duplicate samples were assigned a value of 0·05 mmol/L because d-lactate concentrations were below quantifiable levels (0·1 mmol/L) (Omole et al. 1999). All values were normally distributed (P=0·10) as demonstrated by the Kolmogorov–Smirnov test. "
ABSTRACT: OBJECTIVES: To determine whole blood and serum concentrations of L-lactate and serum concentrations of D-lactate in healthy rabbits and compare three methods of analysis for L-lactate measurement. METHODS: Prospective study using 25 rabbits. Concentrations of whole blood L-lactate were measured using a portable analyser and a blood gas analyser. The remainder of the sample was allowed to clot for centrifugation. Serum was stored at -20 degrees C for determination of L- and D-lactate by high-performance liquid chromatography. RESULTS: D-lactate values by high-performance liquid chromatography were 0.17 +/-0.08 mmol/L. L-lactate values were 5.1 (+/-2.1) mmol/L by high-performance liquid chromatography, 6.9 (+/-2.7) mmol/L with the portable analyser and 7 1 (+/-1.6) mmol/L with the blood gas analyser. No significant difference (P>0.05) was found between the two analysers. Significant difference existed between serum L-lactate values obtained by high-performance liquid chromatography and the whole blood values obtained with the blood gas analyser (P<0.01) and portable analyser (P<0.05). CLINICAL SIGNIFICANCE: Serum concentrations of D-lactate in healthy rabbits are in the range of those of other mammals. L-lactate values in healthy rabbits are higher compared with other mammals. Good correlation was found between the portable and blood gas analysers for whole blood L-lactate measurement in healthy rabbits.Journal of Small Animal Practice 07/2014; 55(9). DOI:10.1111/jsap.12247 · 0.91 Impact Factor
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- "Lactic acid enantiomers (D and L) in the faeces were separated and quantified by high performance liquid chromatography using a Waters 715 Ultra WISP autosampler, a Waters 600 controller and a Waters 486 Tunable Absorbance Ultraviolet detector (Waters, Milford, MA, USA) as previously described (Omole et al., 1999; Ewaschuk et al., 2004) and modified for human samples. Data collection and integration was performed using the Waters Millenium Chromatography Manager version 4 (Waters, USA). "
ABSTRACT: The effects of diets supplemented with either chickpea or its main oligosaccharide raffinose on the composition of the faecal microbial community were examined in 12 healthy adults (18-65 years) in a randomised crossover intervention study. Subjects consumed their usual diet supplemented with soups and desserts that were unfortified, or fortified with either 200 g/d of canned chickpeas or 5 g/d of raffinose for 3 week periods. Changes in faecal bacterial populations of subjects were examined using 16S rRNA-based terminal restriction fragment length polymorphisms (T-RFLP) and clone libraries generated from the diet pools. Classification of the clone libraries and T-RFLP analysis revealed that Faecalibacterium prausnitzii, reported to be an efficient butyrate producer and a highly metabolically active bacterium in the human intestinal microbiota, was more abundant in the raffinose diet and the chickpea diet compared to the control diet. However, no significant difference was observed in the faecal total short chain fatty acid concentration or in the levels of the components (butyrate, acetate and propionate) with the chickpea diet or the raffinose diet compared to the control diet. Bifidobacterium species were detected by T-RFLP in all three diet groups and quantitative real-time PCR (qPCR) analysis showed a marginal increase in 16S rRNA gene copies of Bifidobacterium with the raffinose diet compared to control (P>0.05). The number of individuals showing TRFs for the Clostridium histolyticum - Clostridum lituseburense groups, which include pathogenic bacteria species and putrefactive bacteria, were lower in the chickpea diet compared to the other two treatments. Diet appeared to affect colonisation by a high ammonia-producing bacterial isolate which was detected in 83%, 92% and 42% of individuals in the control, raffinose and chickpea groups, respectively. Our results indicate that chickpea and raffinose have the potential to modulate the intestinal microbial composition to promote intestinal health in humans.Beneficial Microbes 06/2010; 1(2):197-207. DOI:10.3920/BM2009.0027 · 1.50 Impact Factor