title: Establishment of micromethods for macronutrient contents analysis in breast milk.
abstract: Commercially available milk analysers were originally developed for use in the dairy industry, but they are now used to analyse macronutrient content of breast milk in clinical studies and routine care of the premature or very low birthweight (VLBW) infants. Due to the different composition of cow and breast milk, these devices need to be validated against reference methods before they can be used in daily routine. However, current reference methods require a sample volume of 30-100 mL to analyse fat, protein and lactose. It is not feasible to obtain this volume of milk for research purposes, especially from VLBW infants as lactation may be delayed or impaired and the limited volume of breast milk must be provided to the infant. To support validation of milk analysers in both clinical and research settings, the aim of this study is to establish and validate micromethods for precise macronutrient analysis in small volume of breast milk and conduct a feasibility study of the micromethods as a post-validation. Methods include a modified Mojonnier ether extraction (fat), elemental analysis (protein) and ultra-performance liquid chromatography-tandem mass spectrometry (lactose). We were able to downsize volumes required for analysis of fat, protein and lactose to 1 mL, 260 μL and 100 μL; corresponding coefficients of variation are 1.7, 1.8 and 2.3%, respectively. The presented methods allow for reliable and precise analyses of macronutrients in ≤1.5 mL of breast milk and will be used to validate milk analysers.
authors.affiliation: Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Arum
authors.initials: A
authors.lastname: Choi
authors.affiliation: Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fusch
authors.affiliation: Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Niels
authors.initials: N
authors.lastname: Rochow
authors.affiliation: Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Natasha
authors.initials: N
authors.lastname: Sheikh
authors.affiliation: Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Christoph
authors.initials: C
authors.lastname: Fusch
mesh_terms: D000818:Animals; D001942:Breast Feeding; D002853:Chromatography, Liquid; D004041:Dietary Fats / Q000032:analysis; D005240:Feasibility Studies; D005260:Female; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods; D006801:Humans; D007223:Infant; D019102:Infant, Very Low Birth Weight; D007785:Lactose / Q000032:analysis; D016014:Linear Models; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000032:analysis; D008895:Milk, Human / Q000737:chemistry*; D008962:Models, Theoretical; D015203:Reproducibility of Results; D018401:Sample Size; D053719:Tandem Mass Spectrometry
chemical_list: D004041:Dietary Fats; D008894:Milk Proteins; D007785:Lactose
keywords: breast milk; macronutrients; neonatal nutrition; preterm infants; quantitative methods; validation