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Water quality. Sampling. Pt. 5: Guidance on sampling of drinking water and water used for food and beverage processing. Prepared by Technical Committee ISO/TC/147: Water Quality. 1. ed.
1991
Micellar Electrokinetic Chromatography Method for Determination of the Ten Water-Soluble Vitamins in Food Supplements 全文
2013
da Silva, Danielle C. | Visentainer, Jesuí V. | de Souza, Nilson E. | Oliveira, Cláudio C.
The separation and determination of the ten water-soluble vitamins by using capillary electrophoresis in the micellar electrokinetic chromatography in a single run are proposed. The method uses low toxicity and cost solvent (ethanol) as modifier of background electrolyte (BGE) attending to the Green Chemistry principles. The electrophoretic method uses 10.0 % (v/v) ethanol, 2.0 % (w/v) SDS, 0.02 mol L⁻¹borate at pH 8.70 as BGE. The standard and real sample solutions were injected in the eletrophoretic system by hydrodynamic injection under pressure of 0.80 psi for 8 s, and the separation was carried out in a fused silica capillary under a potential of 28 kV at 25 °C; the analytical signals were monitored at 214 nm. The analytical method is precise (r.s.d. < 6 %), accurate (better than 9 %), selective, sensitive, robust, simple, and presents high analytical frequency as ten water-soluble vitamins were separated in only 18 min, with migration times of 5.75 ± 0.02, 6.81 ± 0.02, 8.13 ± 0.04, 8.80 ± 0.07, 8.98 ± 0.06, 11.10 ± 0.08, 11.34 ± 0.05, 13.85 ± 0.15, 14.82 ± 0.04, and 17.85 ± 0.30 min. Detection and quantification limits of 0.34, 0.32, 0.27, 0.20, 2.50, 4.98, 4.92, 0.30, 0.86 and 0.28 mg L⁻¹and 1.02, 0.97, 0.83, 0.62, 7.56, 15.09, 14.91, 0.90, 2.59 and 0.83 mg L⁻¹, for vitamins PP (nicotinamide), B₁₂(cyanocobalamin), B₂(riboflavin), B₆(pyridoxine), B₈(biotin), C (ascorbic acid), B₅(pantothenic acid), B₃(nicotinic acid), B₁(thiamine), and B₉(folic acid), respectively. Excellent recoveries (intra and inter-day) were obtained and, when the method was applied to food supplement analyses the results were in agreement with the conventional HPLC methods.
显示更多 [+] 显示较少 [-]Ultra-sensitive quantification of copper in food and water samples by electrochemical adsorptive stripping voltammetry 全文
2013
Goudarziafshar, Hamid | Nikoorazm, Mohsen | Mortazavi, Sayede Shima | Abbasi, Shahryar | Farmany, Abbas
A new electrochemical adsorptive stripping voltammetry method was developed for the determination of trace amounts of copper in food and water samples. The study of electrochemical behavior of Cu ion indicated that Cu(II) and Schiff base formed a complex in H3BO4-NaOH buffer solution (pH = 7.25). An accumulation potential of -100 mV (vs Ag/AgCl) was applied while the solution was stirred for 60 s. The response curve was recorded by scanning the potential, and the peak current of -0.31 V (vs Ag/AgCl) was recorded. The peak current and concentration of copper accorded with linear relationship in the range of 0.04-120 ng mL(-1). The relative standard deviation (for 12 ng mL(-1) of copper) was 1.73 %, and the detection limit was 0.007 ng mL(-1). The possible interference of some common ions was studied. The proposed method was applied to the determination of copper in water, rice, wheat, tea, milk, and tomato with satisfactory results.
显示更多 [+] 显示较少 [-]The prevalence of bacterial resistance in clinical, food, water and some environmental samples in Southwest Nigeria 全文
2005
The resistance pattern and mechanisms of bacterial isolates obtained from clinical origin, soil, industrial effluent, orange juice products and drinking water were studied using commonly used antibiotics. The microbial load of the water samples, industrial effluent and orange juice products were 1.0 × 10¹−2.25 × 10⁶, 2.15 × 10⁵, and 3.5 × 10⁴−2.15 × 10⁵ cfu mL⁻¹, respectively. The faecal coliform test revealed that only two out of twenty orange juice products had MPN of 2 and 20, the MPN of water ranged from 1−≥1800, while the effluent had MPN of ≥1800. The bacterial isolates that were isolated include E. coli, S. aureus, P. vulgaris, S. marcescens, S. pyogenes, B. cereus, B. subtilis, Micrococcus sp., Klebsiella sp., P. aeruginosa, and Enterobacter sp. Also, clinical and soil isolates of P. aeruginosa were used in the study. Among the eight antibiotics tested for resistance on five strains of each bacterium, seven different resistance patterns were observed among the bacterial isolates obtained from water, effluent and orange juice products. Among the clinical and soil isolates of P. aeruginosa, four multiple-drug resistance patterns were obtained. Thirty strains of E. coli and S. aureus were tested for β-lactamase production and fourteen strains, seven each of E. coli and S. aureus that had high Minimum Inhibitory Concentration values (MIC) for both Amoxycillin and Cloxacillin were positive.
显示更多 [+] 显示较少 [-]Food, water, energy, and macronutrient intake of non-breastfed infants and young children (0–3 years) 全文
2020
Chouraqui, Jean-Pierre | Tavoularis, Gabriel | Simeoni, Umberto | Ferry, Constance | Turck, Dominique
PURPOSE: The French Nutri-Bébé 2013 study aimed to assess the nutritional intake of infants and young children in comparison with the recommendations of the 2013 European Food Safety Authority (EFSA). METHODS: This cross-sectional study enrolled a random sample of families selected according to the Quota sampling method. A 3-day dietary record was conducted and supervised by two face-to-face interviews. All foods and beverages consumed were qualitatively and quantitatively reported in a diary, and their composition calculated using a food composition database. RESULTS: A total of 1035 non-breastfed children were included. Formula was abandoned early, amounting to approximately 50% of the total food intake at 7 months in 50% of infants and 22% at 1 year. A similar trend was observed for specific complementary foods. After 1 year, 50% of children consumed cow’s milk, which was semi-skimmed in 88% of cases. Drinking water intake was low. Protein intake reached 1.4 times the average requirements before 3 months, 2 times at 8–9 months, and > 4 times at 30–35 months. Fat intake was below the EFSA adequate intake (AI) in > 90% of children. Alpha-linolenic acid intake was equal to or greater than the AI in all infants < 3 months, 85% of children at 6 months, 34% at 12–17 months, and 8% >24 months. Regardless of age, docosahexaenoic acid (DHA) intake was less than the AI. CONCLUSION: Strong discrepancies are observed between the actual and recommended intake in young, non-breastfed children namely, a high-protein intake, and a low fat intake, especially DHA.
显示更多 [+] 显示较少 [-]Arsenic intake via water and food by a population living in an arsenic-affected area of Bangladesh 全文
2007
Ohno, K. | Yanase, T. | Matsuo, Y. | Kimura, T. | Rahman, M.H. | Magara, Y. | Matsui, Y.
More and more people in Bangladesh have recently become aware of the risk of drinking arsenic-contaminated groundwater, and have been trying to obtain drinking water from less arsenic-contaminated sources. In this study, arsenic intakes of 18 families living in one block of a rural village in an arsenic-affected district of Bangladesh were evaluated to investigate their actual arsenic intake via food, including from cooking water, and to estimate the contribution of each food category and of drinking water to the total arsenic intake. Water consumption rates were estimated by the self-reporting method. The mean drinking water intake was estimated as about 3 L/d without gender difference. Arsenic intakes from food were evaluated by the duplicate portion sampling method. The duplicated foods from each family were divided into four categories (cooked rice, solid food, cereals for breakfast, and liquid food), and the arsenic concentrations of each food category and of the drinking water were measured. The mean arsenic intake from water and food by all 18 respondents was 0.15 ± 0.11 mg/d (range, 0.043 - 0.49), that by male subjects was 0.18 ± 0.13 mg/d (n = 12) and that by female subjects was 0.096 ± 0.007 mg/d (n = 6). The average contributions to the total arsenic intake were, from drinking water, 13%; liquid food, 4.4%; cooked rice, 56%; solid food, 11%; and cereals, 16%. Arsenic intake via drinking water was not high despite the highly contaminated groundwater in the survey area because many families had changed their drinking water sources to less-contaminated ones. Instead, cooked rice contributed most to the daily arsenic intake. Use of contaminated water for cooking by several families was suspected based on comparisons of arsenic concentrations between drinking water and liquid food, and between rice before and after cooking. Detailed investigation suggested that six households used contaminated water for cooking but not drinking, leading to an increase of arsenic intake via arsenic-contaminated cooking water.
显示更多 [+] 显示较少 [-]Synthesis and application of ion-imprinted polymer nanoparticles for the extraction and preconcentration of mercury in water and food samples employing cold vapor atomic absorption spectrometry 全文
2015
Roushani, Mahmoud | Abbasi, Shahryar | Khani, Hossein
We describe a nanosized Hg(II)-imprinted polymer that was prepared from methacrylic acid as functional monomer, ethyleneglycol dimethacrylate as cross-linker, 2,2′-azobisisobutyronitrile (AIBN) as radical initiator, 2, 2′-di pyrydyl amine as a specific ligand, and Hg (II) as the template ions by precipitation polymerization method in methanol as the progeny solvent. Batch adsorption experiments were carried out as a function of pH, Hg (II) imprinted polymer amount, adsorption and desorption time, volume, and concentration of eluent. The synthesized polymer particles were characterized physically and morphologically by using infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopic techniques. The maximum adsorption capacity of the ion-imprinted and non-imprinted sorbent was 27.96 and 7.89 mg g⁻¹, respectively. Under optimal conditions, the detection limit for mercury was 0.01 μg L⁻¹ and the relative standard deviation was 3.2 % (n = 6) at the 1.00 μg L⁻¹. The procedure was applied to determination of mercury in fish and water samples with satisfactory results.
显示更多 [+] 显示较少 [-]Microbiology of food and animal feeding stuffs. Horizontal method for the enumeration of yeasts and moulds. Pt. 1: Colony count technique in products with water activity greater than 0,95.- pt. 2: Colony count technique in products with water activity less than or equal to 0,95
2008