Tailored amino/hydroxyl bifunctional microporous organic network for efficient stir bar sorptive extraction of parabens and flavors from cosmetic and food samples.

As an effective sample pretreatment approach, stir bar sorptive extraction (SBSE) has shown great prospects in static microextraction and selective enrichment. In this work, bifunctional microporous organic network (B-MON) with the coexistence of amino and hydroxyl groups was firstly designed and synthesized as a novel coating for efficient SBSE of parabens and flavors in combination with high-performance liquid chromatography coupled with photodiode array detection (HPLC-PDA). Linked by covalent bonds to form an extension of the aromatic ring skeleton, B-MON was a tailored adsorbent featured by porous structure and abundant hydrogen bonding sites for analytes with benzene/naphthalene rings and OH/COOH groups. The extraction and desorption parameters were evaluated in detail. Under the optimized conditions, the proposed B-MON-SBSE-HPLC-PDA method offered good linearity (0.10-100 µg L-1) with correlation coefficients R2 ≥ 0.995, low limits of detection (0.010-0.035 µg L-1) and limits of quantification (0.035-0.115 µg L-1), and favorable enrichment factors (40-49). Furthermore, the developed method has been applied to the analysis of parabens and flavors in cosmetic and food samples with recoveries ranging from 80.4 to 109.6%. This method was also feasible to extract the analytes with benzene/naphthalene rings and OH/COOH groups, such as the plant growth regulators and non-steroidal anti-inflammatory drugs. The present study provided a new way to synthesize bifunctional MONs for SBSE of trace analytes in complex samples.

Fabrication of carboxyl functionalized microporous organic network coated stir bar for efficient extraction and analysis of phenylurea herbicides in food and water samples.

Fabrication of novel coatings continues to be an area of great interest and significance in the development and application of stir bar sorptive extraction (SBSE). In this work, a carboxyl-enriched microporous organic network (MON-2COOH) coated stir bar was designed and fabricated as a novel adsorbent for efficient extraction of four phenylurea herbicides (PUHs) before their determination by high-performance liquid chromatography coupled with photodiode array detector (HPLC-PDA). The MON-2COOH was represented as an effective adsorbent for PUHs due to its large surface area, rigid porous structure, aromatic pore walls and the desired hydrogen bonding sites of introduced carboxyl groups. Variables affecting the SBSE of target analytes were optimized in detail. Under the optimal extraction conditions, favorable correlation coefficients (R2 > 0.996) in the linear range 0.10-250 µg L-1, low limits of detection (LODs, S/N = 3) of 0.025-0.070 µg L-1 and good enrichment factors (46-49) were obtained. Besides, the proposed SBSE-HPLC-PDA method was successfully applied to determine trace PUHs in food and environmental water samples with recoveries in the range of 80.0-104.8% and the precisions (relative standard deviations, RSDs) lower than 9.9% (n = 3). This work revealed the potential of MONs in SBSE of trace contaminants from environmental samples.

Pharmacokinetics and effects of demographic factors on blood 25(OH)D3 levels after a single orally administered high dose of vitamin D3.

AIM: To examine the biological consequences and demographic factors that might affect the pharmacokinetics of vitamin D3 after a single high dose intervention in a young Chinese population with vitamin D insufficiency status. METHODS: A total of 28 young subjects (25 to 35 years old) with vitamin D insufficiency status [serum 25(OH)D <30 ng/mL] was recruited in Shanghai, China. The subjects were orally administered a single high dose of vitamin D3 (300 000 IU). Baseline characteristics and blood samples were collected at d 0, 1, 2, 3, 7, 28, 56, 84 and 112 after the intervention. The blood biomarker levels were determined with standardized methods. RESULTS: The intervention markedly increased the blood 25(OH)D3 levels within the first five days (mean Tmax=5.1±2.1 d) and sustained an optimal circulating level of 25(OH)D3 (≥30 ng/mL) for 56 d. After the intervention, body weight and baseline 25(OH)D3 levels were significantly correlated with circulating 25(OH)D3 levels. No adverse events and no consistently significant changes in serum calcium, creatinine, glucose, parathyroid hormone, vitamin D binding protein, or the urinary calcium/reatinine ratio were observed. However, there was a significant increase in phosphorus after the vitamin D3 intervention. Total cholesterol and triglyceride levels were decreased at the end of the trial. CONCLUSION: The pharmacokinetics of vitamin D after intervention were influenced by baseline 25(OH)D3 levels and the body weight of the subjects. The results suggest that a single high oral vitamin D3 intervention is safe and efficient for improving the vitamin D status of young Chinese people with vitamin D insufficiency.

Mineral Intake in Urban Pregnant Women from Base Diet, Fortified Foods, and Food Supplements: Focus on Calcium, Iron, and Zinc.

In the Chinese national nutrition surveys, fortified foods were not investigated separately from the base diet, and the contribution of fortified foods to micronutrients intake is not very clear. This study investigated the diet, including fortified foods and food supplements, of urban pregnant women and analyzed the intake of calcium, iron, and zinc to assess the corresponding contributions of fortified foods, food supplements, and the base diet. The results demonstrated that the base diet was the major source of calcium, iron, and zinc, and was recommended to be the first choice for micronutrients intake. Furthermore, consumption of fortified foods and food supplements offered effective approaches to improve the dietary intake of calcium, iron, and zinc in Chinese urban pregnant women.

[Study on the choice of functional monomer before preparation of myclobutanil molecularly imprinted polymer].

To prepare myclobutanil molecularly imprinted polymer, a method was established for the choice of the appropriate functional monomer and its dosage. UV spectra was applied to study the combination form, the effect intensity, the optimal concentration ratio and the numbers of binding sites between myclobutanil and methyl acrylic acid (MAA) or acrylamide (AM) functional monomer. The results showed that hydrogen-bonding interaction could be formed between myclobutanil and methyl acrylic acid (MAA) or acrylamide (AM) functional monomer. The pi electron of the triazole ring conjugated double bond in my clobutanil could transit to pi* conjugate antibonding orbital when it absorbed energy. The formation of hydrogen bond could make pi-->pi* absorption band transit. Maximum absorption wavelength produced red shift with the increase in the functional monomer concentration in the system. The research revealed that the optimal concentration ratios between myclobutanil and the two monomers were c(M):c(MAA) = 1:4, c(M):c(AM) = 1:2. Myclobutanil and the both the functional monomers had the bonding ability, and strong bonding force. The prepared molecularly imprinted polymer using AM as a functional monomer had better stability and specificity of recognition for myclobutanil.

[Risk assessment of fortification level for vitamin A in food in China].

OBJECTIVE: To study the highest levels for vitamin A voluntary fortification in food by using the principles and methods of risk assessment. METHODS: The dietary nutrient intake data of 68 962 subjects form "Survey on the Status of Nutrition and Health of the Chinese People" in 2002 were analyzed to calculate the highest fortification level of vitamin A in different groups stratified by age, sex and economic development level, using maximum sage fortification level (MSFL) model recommended by European countries. The results were compared with the current national standards of China. RESULTS: The overall results showed that women aged ≥5 0 years had the highest MSFL(2011.5 µgRE/1000 KJ) and the men aged 14 - 17 years had the lowest MSFL (1078.5 µgRE/1000 KJ). The MSFL for pregnant women was 1066.8 µgRE/1000 KJ. The results in different areas showed that men and women aged 14 - 17 years in large city had lower MFSL(997.3 and 879.1 µgRE/1000 KJ respectively). the MSFL in other groups in different areas were between 1000 - 2000 µgRE/1000 KJ. After conversion using the lowest MSFL, the highest fortification levels for vegetable oil, wheat flour, rice, modified milk, biscuit, soybean powder, milk powder for preschool children, milk powder for pregnant and lactating women were 33 063,12 650,12 729,1978,15 929,15 411,20 642,17 920 µgRE/kg respectively,higher than the current fortified level in national standard. CONCLUSION: The current fortification levels in foods are safe and the risk of over intake of vitamin A from fortified food is very low.

[Comparison of the dietary phytosterols intake and serum lipids content in elderly women from three cities of China].

OBJECTIVE: To investigate the dietary phytosterol intake of elderly women in three different cities of China, and to compare the main dietary sources, so that to discuss the relationship of dietary phytosterol intake and serum lipids. METHODS: Based on the dietary pattern, women more than 50 years old from Beijing, Hefei and Urumchi were chosen as testers, 80 - 100 people for each city respectively. The dietary survey was done by continues 24 hours review of two days, the plant food were collected and the phytosterol content (include beta-sitosterol, campesterol, stigmasterol, sitostanol) were analyzed by GC methods, the total phytosterols content were calculated. The dietary phytosterol intake were calculated and serum lipids were also analyzed in all the testers. RESULTS: Testers from Beijing, Hefei and Urumchi were 100, 101 and 84 respectively. The average dietary phytosterol intake of people in Beijing and Hefei were 340.3 mg/d and 313.5 mg/d, the main sources were plant oil and cereals, while the average dietary phytosterol intake of people in Urumchi were 550.4 mg/d, higher than the other two cities (t values were 9.369, 10.420, respectively, both P values < 0.01), the main source in Urumchi was cereal (provide 53.1% of the total phytosterol intake). The laboratory results showed, testers in Urumchi had significantly lower serum TC content ((4.04 +/- 0.78) mmol/L) than that in Beijing ((4.89 +/- 0.91) mmol/L) and Hefei ((4.71 +/- 0.83) mmol/L) (t value were 6.766 and 5.401 respectively, both P values < 0.01); serum TG content in Urumchi((1.01 +/- 0.48) mmol/L) was also lower than that in Beijing ((1.31 +/- 0.53) mmol/L) and Hefei ((1.66 +/- 0.75) mmol/L) (t values were 3.343 and 7.293 respectively, both P values < 0.01); the serum glucose is also lower in testers in Urumchi ((5.02 +/- 2.18) mmol/L) compared with testers in Beijing ((5.69 +/- 1.53) mmol/L, t = 2.561, P < 0.05) and Hefei ((5.78 +/- 1.53) mmol/L, t = 2.934, P < 0.01). CONCLUSION: Different dietary pattern result in significantly different dietary phytosterol intake in elder women in three cities, higher, phytosterol intake seemed to contribute to lower serum lipids.

Contents of phytosterols in vegetables and fruits commonly consumed in China.

OBJECTIVE: To quantify five specific dietary phytosterols and phytostanols in vegetables and fruits commonly consumed in China. METHODS: A total of 34 different kinds of vegetables and 33 kinds of fruits were chosen according to the consuming habit of Chinese people. All the samples were purchased from two shops in Beijing. The contents of phytosterols (beta-sitosterol, campesterol, stigmasterol, beta-sitostanol, and campestanol) were analyzed by GLC method which was established by our laboratory, and the total phytosterols were calculated. RESULTS: The total phytosterol content in vegetables ranged 1.1-53.7 mg/100 g edible portion. The highest concentration was found in pea, cauliflower, broccoli, and romaine lettuce. The phytosterol contents in fruits ranged 1.6-32.6 mg/100 g, the highest concentration was found in navel orange, tangerine, and mango. CONCLUSION: The phytosterol contents in vegetables and fruits are not as high as those in edible oils, but because of the large amount of consumption, they also play an important role in increasing the people's phytosterols intake, indicating that increased intake of vegetables and fruits with higher phytosterol contents helps increase the phytosterol intake in China.

[Effects of phytosterol ester on serum lipid level in rats].

OBJECTIVE: To observed the effects of phytosterol ester (PSE) on serum lipid level in rats. METHODS: (1) Under high-fat fed model, rats were oral administrated either no PSE (model), 4.0, 16.0 or 32.0 mg/kg bw PSE dissolved in oil. After 30 days of this treatment serum was obtained for lipid determination. (2) Ovariectomized rats were randomly assigned to model group, or treated with diethyl stilbestrol (E2, 22.5 microg/kg bw), PSE (32.0 mg/kg bw) or free phytosterol (FPE, 500 mg/kg bw). After fed for 60 days, body weight, liver and uterus weight, serum lipid and estrogen level were measured. In both experiments, another group of normal rats were taken as control. RESULTS: High-fat fed rats administrated with 3 doses of PSE had significantly lower triglyceride (TG) following 30 days of treatment compared to model group. A significant decrease in total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) was observed in 32.0 mg/kg bw PSE group, while a significant increase in high density lipoprotein cholesterol (HDL-C) and ratio of HDL-C/TC was observed in the same group ( P < 0.05). For ovariectomized rats treated with PSE or FPE, a significant lower body and liver weight with lower TC and TG level were observed in comparison with model group (P < 0.05). A little increased uterus weight by PSE and FPE was also observed, though no significant elevation in estrogen was reported. CONCLUSION: Phytosterol ester have potential to decrease hyperlipidemia.

Comparison of ileal digested production of parental rice and rice genetically modified with cowpeas trypsin inhibitor.

OBJECTIVE: To compare the ileal digestibility of protein and amino acids in parental rice and rice genetically modified with sck gene. METHODS: Six experimental swines were surgically fixed with a simple T-cannula at the terminal ileum and fed with parental rice and rice genetically modified with sck gene alternately. The ileum digesta were collected and analyzed for determination of apparent and true digestibility of protein and amino acids. RESULTS: The apparent and true digestibility of protein was similar in these two types of rice. Except for the apparent digestibility of lysine, there was no difference in the apparent and true digestibility of the other 17 amino acids. CONCLUSION: The digestibility of protein and amino acids is not changed by the insertion of foreign gene, so it can meet the request of "substantial equivalence" in digestibility of protein and amino acids.

Effect of micronutrient supplementation on the growth of preschool children in China.

OBJECTIVE: To study the relationship between micronutrient supplementation and children growth. METHODS: A double-blind, placebo-controlled trial was conducted in 156 growth retarded preschool children. They were randomly assigned to five groups: supplemental control (S-control, n = 28), zinc supplementation (+Zn, 3.5 mg Zn/day, n = 34), zinc and calcium supplementation (+ZnCa, 3.5 mg Zn + 250 mg Ca/day, n = 37), zinc and calcium and vitamin A supplementation (+ZnCaVA, 3.5 mg Zn + 250 mg Ca + 200 g VA/day, n = 28), Calcium, and vitamin A supplementation (+CaVA, 250 mg Ca + 200 g VA/day, n = 29). Another 34 children with normal height were selected as normal control (N-control). Supplementation continued for twelve months. RESULTS: The height gain in +Zn group (7.84 cm per year) and +ZnCa group (7.70 cm per year) was significantly higher than that in S-control group (6.74 cm per year, P < 0.05); The weight gain in +ZnCaVA group (2.55 kg per year) and +CaVA group (2.57 kg per year) was also significantly higher than that in S-control group (2.19 kg per year, P < 0.05); The average days of illness in each supplementation group were lower than that in S-control (13 days per year compared with 23 days per year). No significant difference was observed on bone age. CONCLUSION: Zinc and Zinc + Calcium supplementation can improve the height gain, and vitamin A can improve weight gain in growth retarded preschool children, but do not affect the maturity of bone. Micronutrient supplementation can lower the morbidity of these children.