This study provides a fast, accurate and reproducible method for L-ascorbic acid (L-AA) determination in milk samples by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). A small volume of a low toxicity organic solvent (ethanol) was used for degreasing and deproteinization steps. Ethylenediaminetetraacetic acid disodium salt (EDTA) and formic acid were used as stabilizing agents. The method was successfully validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and inter/intra-day precision and applied in raw and processed milk samples. Good linearity (r 2 > 0.9915) and low LOD and LOQ, 1.5 and 5.0 µg L-1 , respectively, were obtained. The recoveries for 500 and 1000 µg L-1 spikes were higher than 90% and the precision values expressed in terms of relative standard deviation (RSD) were ≤ 6.8%. For the first time, the determination of L-AA in a 500 µg L-1 concentration range was reported for milk samples.

Carbon black (CB) grafted with 3-mercaptopropyltrimethoxysilane (3-MPTMS) was used as solid phase extractor for Cd 2+ in a flow injection system coupled to flame atomic absorption spectrometry (FAAS). The influence of pH, buffer concentration, preconcentration flow rate and eluent concentration on preconcentration of Cd 2+ were investigated by means of chemometric tools. The characterization of the adsorbent chemically modified was performed by Fourier transform infrared, scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, Raman spectroscopy and textural analysis. To perform the on-line preconcentration, 20.0 mL of a pH 7.0 Cd 2+ solution at a flow rate of 4.0 mL min −1 was loaded through 30.0 mg of modified CB and then eluted with 1.0 mol L −1 HCl toward the FAAS instrument. The limits of detection and quantification were found to be 0.20 and 0.66 µg L −1 , respectively. Addition and recovery tests carried out in real samples (mineral, tap and saline waters, and cigarette sample) and the analysis of certified reference material (TORT-2, lobster hepatopancreas reference) attested the applicability of proposed method.

Human milk is related to the physiological and nutritional welfare of newborns, providing the necessary dietary energy, physiologically active compounds and essential nutrients for breastfed babies. Human milk fat has an important position as energy source, structural and regulatory functions, being one of the most important components of breast milk. It provides approximately 50-60% of the energy of the human milk, and its composition in fatty acids defines its nutritional and physico-chemical properties. Furthermore, human milk contains the longchain polyunsaturated essential fatty acids (LCPUFA) eicosapentaenoic acid (EPA), arachidonic acid (AA) and docosahexaenoic acid (DHA), which is important for appropriate development of baby's organs, tissues and nervous system. This chapter will address the benefits associated with the consumption of human milk (health, nutritional, immunological and developmental benefits) as well as the analysis applied to determine the lipid quality of this powerful food.

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Human milk is considered the ideal and most complete food for the neonate, due to its balanced nutritional composition, which contributes to the full physical and neurological development of the infant. The lipids present in human milk are sources of saturated, monounsaturated and polyunsaturated fatty acids. The polyunsaturated fatty acids of the omega-6 series, such as linoleic acid and omega-3 series, such as α-linolenic acid, are essential and are also precursors of long-chain polyunsaturated fatty acids, such as arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid, which are involved in a number of functions, such as the development of the nervous system during childhood and the increase in the intelligence quotient of the infant. Due to the lipid importance of human milk, the aim of this review article was to present the analytical methods that are currently being employed to determine its lipid composition. There are few scientific advances in lipid extraction methods and to date, most studies have evaluated the composition of fatty acids by gas chromatography. Liquid chromatography and mass spectrometry have been widely used to identify and quantify different classes of lipids of human milk. O leite humano é considerado o alimento ideal e mais completo para o neonato, devido à sua composição nutricional equilibrada, contribuindo para o pleno desenvolvimento físico e neurológico do lactente. Os lipídios presentes no leite humano são fontes de ácidos graxos saturados, monoinsaturados e poliinsaturados. Os ácidos graxos poli-insaturados da série ômega-6, como o ácido linoleico e da série ômega-3, como o α-linolênico, são essenciais e também são precursores de ácidos graxos poli-insaturados de cadeia longa, como o ácido araquidônico, ácido eicosapentaenoico e ácido docosahexaenoico, que estão envolvidos no desenvolvimento do sistema nervoso e no aumento do quociente de inteligência do lactente. Devido à importância lipídica do leite humano, o objetivo deste artigo de revisão foi apresentar os métodos analíticos que têm sido atualmente mais empregados para determinar sua composição lipídica. Há poucos avanços científicos quanto aos métodos de extração lipídica e até o presente momento, grande parte dos estudos avaliaram, a composição em ácidos graxos, a partir de cromatografia em fase gasosa. A cromatografia líquida e a espectrometria de massas têm sido utilizadas para identificação e quantificação de distintas classes lipídicas presentes no leite humano.