Liquid-Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting.
Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid-liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis.
Pediatrics Genetic and Research Laboratory, Department of Pediatrics, New Medical Block, Opposite Old Casualty, Lok Nayak Hospital, Maulana Azad Medical College, New Delhi, 110002 India.
Chandrawati
C
Kumari
Pediatrics Genetic and Research Laboratory, Department of Pediatrics, New Medical Block, Opposite Old Casualty, Lok Nayak Hospital, Maulana Azad Medical College, New Delhi, 110002 India.
Bijo
B
Varughese
Department of Neonatology, Associated Lok Nayak Hospital, Maulana Azad Medical College, New Delhi, 110002 India.
Siddarth
S
Ramji
Pediatrics Genetic and Research Laboratory, Department of Pediatrics, New Medical Block, Opposite Old Casualty, Lok Nayak Hospital, Maulana Azad Medical College, New Delhi, 110002 India.
Seema
S
Kapoor
Gas chromatography mass spectrometry; Liquid–liquid extraction; Organic acidemia; Solid phase extraction; Urinary organic acids