title: Quantification of myo-inositol, 1,5-anhydro- D-sorbitol, and D-chiro-inositol using high-performance liquid chromatography with electrochemical detection in very small volume clinical samples.
abstract: Inositol is a six-carbon sugar alcohol and is one of nine biologically significant isomers of hexahydroxycyclohexane. Myo-inositol is the primary biologically active form and is present in higher concentrations in the fetus and newborn than in adults. It is currently being examined for the prevention of retinopathy of prematurity in newborn preterm infants. A robust method for quantifying myo-inositol (MI), D-chiro-inositol (DCI) and 1,5-anhydro- D-sorbitol (ADS) in very small-volume (25 μL) urine, blood serum and/or plasma samples was developed. Using a multiple-column, multiple mobile phase liquid chromatographic system with electrochemical detection, the method was validated with respect to (a) selectivity, (b) accuracy/recovery, (c) precision/reproducibility, (d) sensitivity, (e) stability and (f) ruggedness. The standard curve was linear and ranged from 0.5 to 30 mg/L for each of the three analytes. Above-mentioned performance measures were within acceptable limits described in the Food and Drug Administration's Guidance for Industry: Bioanalytical Method Validation. The method was validated using blood serum and plasma collected using four common anticoagulants, and also by quantifying the accuracy and sensitivity of MI measured in simulated urine samples recovered from preterm infant diaper systems. The method performs satisfactorily measuring the three most common inositol isomers on 25 μL clinical samples of serum, plasma, milk, and/or urine. Similar performance is seen testing larger volume samples of infant formulas and infant formula ingredients. MI, ADS and DCI may be accurately tested in urine samples collected from five different preterm infant diapers if the urine volume is greater than 2-5 mL.
authors.affiliation: Abbott Nutrition, 3300 Stelzer Road, Columbus, OH, 34219, USA.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Schimpf
authors.affiliation: School of Pharmacy, Texas Tech University Health Sciences Center, 5920 Forest Park Road - Suite 400, Dallas, TX, 75235, USA.
authors.forename: Claudia C
authors.initials: CC
authors.lastname: Meek
authors.affiliation: School of Pharmacy, Texas Tech University Health Sciences Center, 5920 Forest Park Road - Suite 400, Dallas, TX, 75235, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Leff
authors.affiliation: University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Pediatrics, Box 651, Rochester, NY, 14642, USA.
authors.forename: Dale L
authors.initials: DL
authors.lastname: Phelps
authors.affiliation: Abbott Nutrition, 3300 Stelzer Road, Columbus, OH, 34219, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Schmitz
authors.affiliation: Abbott Nutrition, 3300 Stelzer Road, Columbus, OH, 34219, USA.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Cordle
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D006801:Humans; D007294:Inositol / Q000032:analysis* / Q000097:blood / Q000652:urine; D007536:Isomerism; D007547:Isosorbide / Q000032:analysis* / Q000097:blood / Q000652:urine; D012015:Reference Standards
chemical_list: D007294:Inositol; D007547:Isosorbide
keywords: LC; clinical samples; diapers; inositol; sorbitol