title: Quantification of total hexose on dry blood spot by tandem mass spectrometry.
abstract: BACKGROUND
  Because hypoglycemia and hyperglycemia are harmful and not always associated with overt clinical signs, it is necessary to have methods available to screen for glucose levels to detect hypoglycemia and diabetes as early as possible. A new method for such screening and the clinical determination of blood total hexose on a dry blood spot (DBS) using tandem mass spectrometry (MS/MS) was developed.
  
  
  METHODS
  The serum glucose controls and blood were prepared as DBS and then extracted into a methanol solution containing isotope-labeled internal standards. The methanolic extraction was subjected to HPLC, followed by MS/MS in positive ion mode. Multiple-reaction monitoring of m/z 203.1→23 was used to detect hexose, and m/z 209.0→23 was used for 13C6-D-glucose.
  
  
  RESULTS
  The recoveries of blood glucose by MS/MS were 90%-102% with an R(2) value of 0.999 after linear regression (p<0.001). The controls were within an acceptable range, and the coefficients of variation were less than 10%. The blood total hexose in neonates aged 3-7 days (6.41±1.46 mmol/L) was lower than that in neonates aged 8-30 days (6.66±1.38 mmol/L), and it was lower in neonates than in children aged 1-72 months (7.19±1.87 mmol/L).
  
  
  CONCLUSIONS
  Quantification of total hexose on a dry blood spot by MS/MS is accurate, reliable and feasible for screening and clinical tests.
authors.affiliation: Children's Hospital of Shanghai/Children's Hospital affiliated with Shanghai Jiaotong University, China. gongzh1963@163.net
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Gong
authors.forename: Guoli
authors.initials: G
authors.lastname: Tian
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Huang
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Wang
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Ge
mesh_terms: D002138:Calibration; D002648:Child; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques; D059788:Dried Blood Spot Testing; D005690:Galactose / Q000097:blood; D005947:Glucose / Q000737:chemistry; D006601:Hexoses / Q000097:blood* / Q000737:chemistry; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D012016:Reference Values; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D006601:Hexoses; D005947:Glucose; D005690:Galactose