Determination of phase II drug metabolites in equine urine by micellar electrokinetic capillary chromatography

Taylor, M.R.S.; Westwood, Steven A.; Perrett, David

doi:10.1016/0021-9673(96)00380-9

Cited by 21 publications

(6 citation statements)

References 18 publications

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“…Confirmatory methods using GC-MS [1][2][3] and LC-MS/MS [2][3][4][5] on selected quaternary ammonium drugs have been developed but with GC-MS intact quaternary ammonium compounds cannot be analysed. CE has been used to analyse basic and acidic drugs in urine and plasma [6][7][8][9][10]. It has also been used to analyse steroid conjugates [11].…”

Section: Introductionmentioning

confidence: 99%

Analyses of quaternary ammonium drugs in horse urine by capillary electrophoresis - mass spectrometry

2001

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A capillary electrophoresis-mass spectrometry (CE-MS) method for the analysis of quaternary ammonium drugs in equine urine was developed. Quaternary ammonium drugs were first extracted from equine urine by ion-pair extraction and then analysed by CE-MS in the positive electrospray ionization (ESI) mode. Within 12 min, eight quaternary ammonium drugs, each at 1 ng/mL in horse urine, could be detected. The confirmation of these drugs in urine samples was achieved by capillary electrophoresis tandem mass spectrometry (CE-MS/MS). A direct comparison of this method was made with existing liquid chromatography/mass spectrometry (LC-MS) methods in the detection and confirmation of glycopyrrolate and ipratropium bromide in horse urine. While the two drugs could be detected within the same CE-MS run at 1 ng/mL in urine, they could only be detected in separate LC-MS runs at 5 ng/mL in urine. In addition, CE-MS consumed a much smaller volume of extract; the analyte peak widths, in some cases, were much narrower; and as the quaternary ammonium ions were well separated electrophoretically from the mainly neutral urine matrix, a much cleaner background in the CE-MS total ion trace was observed.

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Section: Introductionmentioning

confidence: 99%

Analyses of quaternary ammonium drugs in horse urine by capillary electrophoresis - mass spectrometry

2001

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“…The samples were extracted by solid phase with detection at 195 nm by diode array detection. The separation was completed in less than 10 min [83]. A few drugs of abuse (amphetamines, morphine, acetaminophen, codeine) were initially screened in biological fluids using a short capillary (2 min analysis) and identified with a longer capillary (18 min separation).…”

Section: Forensicmentioning

confidence: 99%

Analysis of small molecules for clinical diagnosis by capillary electrophoresis

Shihabi

Friedberg

1997

Electrophoresis

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The application of capillary electrophoresis (CE) for the analysis of small molecules in clinical research is growing steadily. Initial studies have dealt with separations of standards or compounds in clean matrices. However, later studies dealt with analysis of those compounds in serum, urine or tissues. Great progress has been accomplished in three areas of clinical interest: organic acids, amino acids and drug analysis. The analysis of these compounds by capillary electrophoresis has several distinct advantages: high resolution, simplicity, versatility and especially low operating costs. In many cases, the sample can be injected directly without complex pretreatment. Most of the described methods have been validated for their precision, linearity and accuracy. In forensic toxicology, the CE has been used for drug identification and as a complementary analytical method.

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“…MEKC, applicable to both ionic and neutral species, has proved to be a useful tool in the study of different target metabolites in urine [15][16][17][18]. However, its application as a nontargeted approach has not yet been fully exploited.…”

Section: Introductionmentioning

confidence: 99%

“…CE has recently been incorporated to the family of metabolic fingerprinting techniques used for clinical studies [11][12][13][14]. CE is an efficient and sensitive high-resolution separation technique that allows fast analysis of ionic species and the use of small samples.MEKC, applicable to both ionic and neutral species, has proved to be a useful tool in the study of different target metabolites in urine [15][16][17][18]. However, its application as a nontargeted approach has not yet been fully exploited.…”

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confidence: 99%

Data processing in metabolic fingerprinting by CE‐UV: Application to urine samples from autistic children

Soria

Wright²,

Goodall

et al. 2007

Electrophoresis

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Data processing in metabolic fingerprinting by CE-UV: Application to urine samples from autistic childrenMetabolic fingerprinting of biofluids such as urine can be used to detect and analyse differences between individuals. However, before pattern recognition methods can be utilised for classification, preprocessing techniques for the denoising, baseline removal, normalisation and alignment of electropherograms must be applied. Here a MEKC method using diode array detection has been used for high-resolution separation of both charged and neutral metabolites. Novel and generic algorithms have been developed for use prior to multivariate data analysis. Alignment is achieved by combining the use of reference peaks with a method that uses information from multiple wavelengths to align electropherograms to a reference signal. This metabolic fingerprinting approach by MEKC has been applied for the first time to urine samples from autistic and control children in a nontargeted and unbiased search for markers for autism. Although no biomarkers for autism could be determined using MEKC data here, the general approach presented could also be applied to the processing of other data collected by CE with UV-Vis detection. Keywords IntroductionMetabolic fingerprinting approaches [1] have recently emerged as a nonbiased alternative to the determination of individual levels of a specific metabolite or class of metabolites in large sets of samples, as is necessary for clinical diagnosis purposes. 1 H-NMR has been widely used in urinary fingerprinting and the search for disease biomarkers [2,3]. The approach has been recently complemented by chromatographic techniques hyphenated to MS (GC-MS and LC-MS), with the advantage over 1 H-NMR of a higher sensitivity [4][5][6][7]. Other spectroscopic techniques used less frequently for urinary fingerprinting include direct injection MS [8,9] and FTIR spectroscopy [10]. CE has recently been incorporated to the family of metabolic fingerprinting techniques used for clinical studies [11][12][13][14]. CE is an efficient and sensitive high-resolution separation technique that allows fast analysis of ionic species and the use of small samples.MEKC, applicable to both ionic and neutral species, has proved to be a useful tool in the study of different target metabolites in urine [15][16][17][18]. However, its application as a nontargeted approach has not yet been fully exploited. CD-modified MEKC allows the separation of over 80 UVabsorbing endogenous analytes of different charge types (neutral, anionic and cationic) below 25 min [18][19][20]. Since minimal sample pretreatment is required, this methodology has the potential for high-throughput analysis of the large number of samples required in screening applications.Urinary fingerprints produced by MEKC are highly complex datasets and require multivariate techniques for interpretation. Unsupervised pattern recognition methods such as cluster analysis and principal component analysis (PCA) have been used to examine the structure of these dataset...

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Determination of phase II drug metabolites in equine urine by micellar electrokinetic capillary chromatography

Cited by 21 publications

References 18 publications

Analyses of quaternary ammonium drugs in horse urine by capillary electrophoresis - mass spectrometry

Analyses of quaternary ammonium drugs in horse urine by capillary electrophoresis - mass spectrometry

Analysis of small molecules for clinical diagnosis by capillary electrophoresis

Data processing in metabolic fingerprinting by CE‐UV: Application to urine samples from autistic children

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