Simultaneous determination of lipoic acid (LA) and dihydrolipoic acid (DHLA) in human plasma using high-performance liquid chromatography coupled with electrochemical detection

Khan, Abad; Iqbal, Zafar; Watson, David; Khan, Amirzada; Khan, Inamullah; Muhammad, Naveed; Muhammad, S.; Nasib, Hashmat Ara; Iqbal, Naveed; Faiz-ur-Rehman,; Kashif, Muhammad

doi:10.1016/j.jchromb.2011.04.017

Cited by 23 publications

(21 citation statements)

References 28 publications

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“…The LOD was better than the values reported in previous studies, 2.4 nmo/L and 4.9 nmol/L (Khan et al, 2011;Teichert & Preiss, 2002, respectively). The LOD was better than the values reported in previous studies, 2.4 nmo/L and 4.9 nmol/L (Khan et al, 2011;Teichert & Preiss, 2002, respectively).…”

Section: Resultscontrasting

confidence: 69%

“…We combined and modified previous methods (Teichert & Preiss, 1992, 1995, 1997, 2002Khan et al, 2010Khan et al, , 2011. We combined and modified previous methods (Teichert & Preiss, 1992, 1995, 1997, 2002Khan et al, 2010Khan et al, , 2011.…”

Section: Resultsmentioning

confidence: 99%

“…Montero, Ramírez, Sánchez, and Gonzáles (2012) gave undetectable contents for LA in human plasma. On the other hand, Khan et al (2011) published that the range is 143.7-197.0 nmol/L.…”

Section: Introductionmentioning

confidence: 99%

“…However, in 2002 these same authors assumed that levels are 4.9 nmol/L or less (Teichert & Preiss, 2002). On the other hand, Khan et al (2011) published that the range is 143.7-197.0 nmol/L. On the other hand, Khan et al (2011) published that the range is 143.7-197.0 nmol/L.…”

Section: Introductionmentioning

confidence: 99%

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The issue of HPLC determination of endogenous lipoic acid in human plasma

Sechovcová

Královcová

Kanďár

et al. 2018

Biomedical Chromatography

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Lipoic acid (LA) is used extensively as a therapeutic agent for the treatment of various diseases. Many methods have been reported for the determination of LA plasma levels and its metabolites after its supplementation, but available information concerning endogenous plasma levels is still scarce. Studies which directly focused on determining the endogenous plasma levels provided highly controversial results, <4.9 nmol/L or 143.7-197.0 nmol/L. The main aim of this study was to verify the levels of free LA in the plasma of 40 individuals (17 women, 23 men). This group was nonsupplemented with LA and met the conditions for incorporation into the blood donors register. We measured the levels of LA using an HPLC method with very sensitive coulometric detection after previous sample preparation including deproteination and solid-phase extraction with a Phenyl cartridge. Our limit of detection was 1.85 nmol/L and was better than the values reported in studies that directly focused on determining the endogenous plasma levels of LA: 2.4 and 4.9 nmol/L respectively. However, the levels of free LA in the plasma of nonsupplemented voluntary blood donors were not detectable in all cases. The presented results of our study show that endogenous concentrations of LA are <1.85 nmol/L.

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Section: Resultscontrasting

confidence: 69%

Section: Resultsmentioning

confidence: 99%

“…Montero, Ramírez, Sánchez, and Gonzáles (2012) gave undetectable contents for LA in human plasma. On the other hand, Khan et al (2011) published that the range is 143.7-197.0 nmol/L.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The issue of HPLC determination of endogenous lipoic acid in human plasma

Sechovcová

Královcová

Kanďár

et al. 2018

Biomedical Chromatography

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show abstract

“…Routine cleaning of the surface of the electrode was performed to maintain the sensitivity [19]. In this way, the results obtained from skin analyses are reproducible and accurate as reported for LA in plasma samples [25]. Therefore, HPLC/EC may be applied to samples with low concentrations of LA.…”

Section: La Analysis By Hplc/ecmentioning

confidence: 93%

Quantification of lipoic acid from skin samples by HPLC using ultraviolet, electrochemical and evaporative light scattering detectors

Campos

Praça

Bentley

2016

Journal of Chromatography B

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Determination of lipoic acid in human urine by capillary zone electrophoresis

Kubalczyk

Głowacki

2017

Electrophoresis

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Fast, simple, and accurate CE method enabling determination of lipoic acid (LA) in human urine has been developed and validated. LA is a disulfide-containing natural compound absorbed from the organism's diet. Due to powerful antioxidant activity, LA has been used for prevention and treatment of various diseases and disorders, e.g. cardiovascular diseases, neurodegenerative disorders, and cancer. The proposed analytical procedure consists of liquid-liquid sample extraction, reduction of LA with tris(2-carboxyethyl)phosphine, derivatization with 1-benzyl-2-chloropyridinium bromide (BCPB) followed by field amplified sample injection stacking, capillary zone electrophoresis separation, and ultraviolet-absorbance detection of LA-BCPB derivative at 322 nm. Effective baseline electrophoretic separation was achieved within 6 min under the separation voltage of 20 kV (∼80 μA) using a standard fused-silica capillary (effective length 51.5 cm, 75 μm id) and BGE consisted of 0.05 mol/L borate buffer adjusted to pH 9. The experimentally determined limit of detection for LA in urine was 1.2 μmol/L. The calibration curve obtained for LA in urine showed linearity in the range 2.5-80 μmol/L, with R 0.9998. The relative standard deviation of the points of the calibration curve was lower than 10%. The analytical procedure was successfully applied to analysis of real urine samples from seven healthy volunteers who received single 100 mg dose of LA.

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Simultaneous determination of lipoic acid (LA) and dihydrolipoic acid (DHLA) in human plasma using high-performance liquid chromatography coupled with electrochemical detection

Cited by 23 publications

References 28 publications

The issue of HPLC determination of endogenous lipoic acid in human plasma

The issue of HPLC determination of endogenous lipoic acid in human plasma

Quantification of lipoic acid from skin samples by HPLC using ultraviolet, electrochemical and evaporative light scattering detectors

Determination of lipoic acid in human urine by capillary zone electrophoresis

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