Determination of vitamin B12 in infant formula and adult nutritionals using HPLC after purification on an immunoaffinity column: first action 2011.09.

During the "Standards Development and International Harmonization: AOAC INTERNATIONAL Mid-Year Meeting," on June 29, 2011, the method "Determination of vitamin B12 in infant formula and adult nutritionals using HPLC after purification on an immunoaffinity column" was recommended by an Expert Review Panel and adopted as AOAC Official First Action status. The method is applicable for the determination of vitamin B12 in milk-based infant formula. Vitamin B12 is extracted from the sample in sodium acetate buffer in the presence of potassium cyanide. After purification and concentration with an immunoaffinity column (IAC), vitamin B12 is determined by LC with UV detection (361 nm). Data supplied by CLF demonstrated linear response over a wide range of concentrations (1.4-39 microg/100 mL). The analytical range is 0.2-10 microg/100 g, depending on the capacity of the IACs (0.01-0.5 microg), the input weight, and dilutions. Recovery rates were assessed using National Institute of Standards and Technology SRM 1849, and determined to be 95.1%, with SD of 0.34 and CV of 9.0. Measurement uncertainty (UE) was 0.8 microg/100 g, which was calculated from the validation data. It is an expanded measurement uncertainty and was obtained through multiplication with a coverage factor k. LOQ values were reported as 0.10 microg/100 g. The performance characteristics of the method met the standard method performance requirements set forth by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals; thus, the method was determined to be appropriate for First Action status.

Estudo multicentro da fluorose dental e da cárie dental em escolares de 7 e 10 anos de Belo Horizonte: parte I / Multicentric study of dental fluorose and dental caries in 7-and in 10-year-old schoolchildren from Belo Horizonte, Brazil-Part I

Este estudo transversal examinou 797 escolares de 7 a 10 anos, de seis diferentes setores urbanos de Belo Horizonte, pretendendo verificar a prevalência da fluorose dentária e sua relaçäo com a cárie dental, estado nutricional, exposiçäo à água fluoretada e gênero. Os resultados aqui apresentados referem-se às crianças de 7 anos. Os indicadores utilizados foram CPOS/ceos, Indice de Dean e relaçäo peso/altura. Para verificaçäo da concentraçäo de flúor na água, análises de cromatografia líquida foram realizadas. Os resultados deste estudo mostram que a fluorose branda é o tipo mais comum aos 7 anos. A variaçäo na ocorrência da fluorose entre os fatores é significativa (p = 0,04), sendo que o setor 2 (Santo André) apresentou a maior prevalência (69,3 por cento), e o 3 (Ouro Preto), a menor prevalência (45,59 por cento). Os setores com maior prevalência de fluorose foram aqueles que apresentaram a menor prevalência de cárie dental, mas esta reaçäo näo foi comprovada matematicamente (p = 0,07). Segundo ainda esse modelo, as variáveis sexo e concentraçäo de flúor na água näo interferem no comportamento da fluorose; entretanto, as crianças subnutridas apresentam