ABSTRACT
Heavy metal residue in vegetables is a big concern in the whole world.The aim of this work is to explore the effect of multivariable selection on analyzing Cd in Chinese cabbage polluted in lab by collecting the spectra of laser induced breakdown spectroscopy (LIBS) from the samples.At the same time,the actual Cd content in samples was obtained by anodic stripping voltammetry (ASV).The LIBS spectral range in partial least square (PLS) model was screened by standard normal variable transformation (SNV),first derivative (FD),second derivative (SD) and center treatment (CT) for preprocessing spectra and the optimized method was used for the analysis of interval partial least square (iPLS) and synergy interval partial least square (SiPLS).The results indicated that the method of CT was the best as a comparison with PLS,iPLS and SiPLS.And the intervals of wavelength were 214.72-215.82 nm,215.88-216.97 nm and 225.08 -226.35 nm by utilizing the optimized SiPLS.Here the root mean square error of cross validation (RMSECV) between real content and predicted ones was 1.487,the root mean squared error of prediction (RMSEP) was 1.094,the correlation coefficient (R) was 0.9942,and the average relative error (ARE) was 11.60％.The results displayed that LIBS could predict Cd in vegetables by multivariable selection of SiPLS and the accuracy could meet the requirement of rapid and green analysis of Cd in vegetables.
ABSTRACT
OBJETIVO: relacionar a concentração de cádmio do colostro materno com o estilo de vida das puérperas. MÉTODOS: estudo transversal, realizado em Goiânia, Goiás (região Centro-Oeste do Brasil). Participaram da pesquisa 80 mulheres, de acordo com critérios de inclusão, entrevistadas sobre características socioeconômicas e estilo de vida. Elas responderam a um questionário de frequência de consumo alimentar (QFCA). As amostras de colostro coletadas foram analisadas por espectrometria de absorção atômica por chama para quantificar os níveis de cádmio. Na análise estatística, além de medidas de tendência central, foram realizados os testes de Mann-Whitney e de Kruskal-Wallis, correlação e regressão. RESULTADOS: a média da concentração de cádmio foi de 2,3 μg/L, e a mediana de 0,9 μg/L. Variáveis como idade e paridade resultaram em correlação positiva não significativa com os níveis de cádmio no colostro. O hábito de fumar não se relacionou significativamente com o cádmio. CONCLUSÕES: a alimentação da puérpera influencia o nível de cádmio do colostro, especialmente o originado de alimentos vegetais, como cereais.
PURPOSE: to relate the cadmium concentration of colostrum with the lifestyle of women in the puerperium period. METHODS: a cross-sectional study was conducted in Goiânia, Goiás (Mid-western Region of Brazil). Eighty women, according to inclusion criteria, were interviewed about their socioeconomic characteristics and lifestyle. They answered a questionnaire about food frequency consumption (FFQ). The colostrum samples collected were analyzed by flame atomic absorption spectrometry to quantify cadmium levels. For statistical analysis, central tendency measures were obtained, and the Mann-Whitney and Kruskal-Wallis tests were performed, as well as correlation and regression tests. RESULTS: the average cadmium concentration was 2.3 µg/L and the median was 0.9 µg/L. Variables such as age and parity showed a nonsignificant positive correlation with cadmium. Smoking habit was not significantly associated with cadmium. CONCLUSIONS: postpartum food intake influences the level of cadmium in colostrum, especially vegetables such as cereals.