TALANTA
·
2014
·
IF 3.511
Jiang Liu,Han Song,Jie Liu,Yuan Liu,Le Li,Hui Tang,Yingchun Li
In this study, a rapid and accurate determination strategy was established for simultaneous measurement of melamine (MLM) and dicyandiamide (DCD) directly in powdered milk by coupling molecularly imprinted solid-phase extraction (MISPE) with high performance liquid chromatography (HPLC). A novel double-template technique was adopted for preparing SPE packing agent and the obtained double-templated (MLM and DCD) molecularly imprinted polymers (MD-MIPs) was characterized by Fourier-transform infrared spectroscopy and scanning electron microscope (SEM). The molecular recognition ability and the binding capability of the as-prepared polymers towards MLM and DCD were evaluated via static and dynamic binding tests, and it was found that the MD-MIPs showed better affinity and selectivity for both templates compared with single-templated MIPs and non-imprinted polymers (NIPs). An approach based on MISPE and HPLC was then developed and optimized to detect MLM and DCD in powdered milk. The detection limit of the method ( S / N =3) were 0.13 μg/g for MLM and 0.07 μg/g for DCD, and the relative standard deviation (RSD) of intra-day and inter-day determination for MLM was 3.3% and 4.7%, and 3.5% and 5.9% for DCD. The recoveries in MLM and DCD analysis at three spiked levels were 93.1–100.1% and 75.7–82.5%, respectively, with all RSD less than 5.2%.
研究领域:
分析化学
·
食品安全
✓ 已验证
DOI
高影响因子
Toxics
·
2023
·Vol. 11
·期 9
·799
·
IF 4.6
Hangwei Wang,Zhanren Liu,Shaojie Liu,Ruoru Yang,Yifei Wang,Yiying Gu,Min Wu,Ruihua Dong,Bo Chen
This study aimed to assess the therapeutic efficacy of catechin against experimentally induced kidney stones resulting from co-exposure to melamine (MEL) and cyanuric acid (CYA) in male Sprague–Dawley rats. To induce nephrolithiasis, a combination of MEL and CYA (1:1 ratio, each at a dose of 31.5 mg/kg bw/day) was administered to the rats for 28 consecutive days. After nephrolithiasis was successfully induced, the rats were randomly divided into two groups: a treatment group and a sham group. The treatment group was given a daily oral dose of 50 mg/kg of catechin for 28 days, while the sham group received no intervention. Urine and blood samples were collected throughout the treatment period, and kidney samples were taken on day 28. Our findings demonstrated that treatment with catechin significantly reduced crystal deposition and pathological damage in the rats from nephrolithiasis. Additionally, renal injury markers were significantly decreased in the treatment group compared to the sham group. These findings suggest that catechin has potential therapeutic benefits in treating nephrolithiasis induced by co-exposure to MEL and CYA.Keywords:melamine;cyanuric acid;nephrolithiasis;catechin
研究领域:
毒理学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2012
·
IF 2.545
Wei Feng,Changyin Lv,Liping Yang,Jianlin Cheng,Chengyan Yan
Melamine, a basic organic chemical intermediate, can cause renal failure because of the formation of insoluble melamine cyanurate crystals in the kidneys. This study examined a novel fluorescence spectrometry for the determination of trace melamine in dairy. The method was based on the inhibitory effect of melamine on the decolorizing reaction of the uncatalytic oxidation of acridine red by potassium permanganate in a sulfuric acid medium. The calibration graph was linear for melamine concentrations of 2.1 × 10 −4 –1.6 mg/L, and a detection limit of 61.5 ng/L was obtained. The melamine was determined in dairy samples by the proposed method after liquid–liquid and solid phase extraction. The results correlated with the high-performance liquid chromatography. The recoveries were within the range of 99.6–103.3% for liquid milk and 98.5–111.1% for milk powder. The possible mechanism of the reaction was also investigated by ultraviolet spectra.
研究领域:
分析化学
·
食品安全
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 16
·7924-7931
·
IF 3.269
Aiping Gao,Yiran Li,Haiting Lv,Dan Liu,Na Zhao,Qianqian Ding,Xinhua Cao
In this study, a new gelator containing lenalidomide and cholesterol groups was synthesized, which could form stable gels in 1,4-dioxane and mixed solvents of DMF/H2O (v/v, 1/1). The self-assembly process was studied and certified by field emission scanning electron microscopy, UV-vis, IR, XRD, and CA. Based on the results obtained from the abovementioned analyses, the self-assembly structure, aggregation pattern, and surface wettability could be tuned via the addition of melamine due to intermolecular hydrogen bonding between compound 1 and melamine (MA). The irregular lumpy and the closely packed fiber structures could be turned into microbelt and sparse fiber structures after the addition of MA, respectively. Moreover, the hydrophobicity of the xerogel film of 1-MA was obviously increased. The mechanical strength of gel 1-MA was obvisously enhanced due to the addition of MA. The UV-vis, IR, and XRD experiment results showed that the self-assembly process and mode of 1 was changed due to the addition of MA through intermolecular hydrogen bonding between 1 and MA. Therefore, these results provide a method for the regulation of the self-assembly process via intermolecular noncovalent interaction.
研究领域:
化学
·
材料科学
·
生物医学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2015
·
IF 3.368
Ling Zhu,Guanhong Xu,Fangdi Wei,Jing Yang,Qin Hu
A novel molecularly imprinted stir bar (MIP-SB) was developed with melamine (MA) as the template molecule in this study. The sorptive capacity of MIP-SB was nearly three times over that of non-imprinted stir bar (NIP-SB). The MIP-SB presented much better selectivity than NIP-SB when used to absorb MA and its analogues. An analytical method to determine MA in powdered milk was established by combining MIP-SB sorptive extraction with HPLC. The liner range was 0.0631–12.6 ng/mL with good correlation coefficient of 0.9983, and the limit of detection was 0.0127 ng/mL based on three times ratio of signal to noise. This method was successfully applied to the determination of MA in powdered milk with satisfactory results. The method built is simple and suitable for the determination of MA in milk products which is of great significance for quality control of milk products.
研究领域:
分析化学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD PROCESS ENGINEERING
·
2018
·Vol. 42
·期 2
·e12976
·
IF 1.955
Ning Yang,Liang-Liang Xie,Chen Pan,Min-Feng Yuan,Zhi-Han Tao,Han-Ping Mao
Ubiquitous food security control is desirable. However, the analysis methods, such as those for milk, are highly based on manual analysis, leading to low efficiency. Thus, we report a multilayer paper-based microfluidic chip transforming chromatic readout to electric signals. First, colloidal gold immunochromatographic assays (GICA) are used to achieve the colorimetric occurrence. Secondly, the test (T) lines and control (C) lines are patterned to encode different EAN-8 barcode. Furthermore, accurate scanning is accomplished by the automatic threshold segmentation. These technologies make the digital determination of melamine (MEL) and chloramphenicol (CAP) by phone readily accessible. Results indicate that the accurate machine-scanning can be assured when MEL and CAP is above 30 ng/mL and 6 ng/mL in milk respectively. The detection time is under 8 min, and the stable storage life is over 90 days. Therefore, this simple chip allows rapid, machine-readable, electric-recordable diagnostic directly from chromatic assays with satisfying stability, specificity and accuracy. Practical applications This article illustrates a method used to determine the concentration of melamine and chloramphenicol in milk. When melamine and chloramphenicol is above 30 and 6 ng/ml in milk, the produced EAN-8 barcode can be recognized with high accurate level, compared with international standards, the results are acceptable and sensitive. This method is highly intellectual and environmentally friendly, with the disposable materials and instant smartphone-readable EAN-8 results patterns. This article demonstrates a multilayer paper chip based on EAN-8 encoding rules, colloidal gold nanoparticles, and immunochromatographic assays. The EAN-8 format assay is achieved by color-development occurrence of colloidal GICA in different encoding areas of EAN-8 code, and the analysis device, namely smartphone, is accessible by almost every individual. Therefore, this chip can pave a potential way for massive health control and digital automated analysis for daily life and industrial manufacture.
研究领域:
食品安全
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yonggan Ju,Jingxian Hua,Yawei Gu,Hongling Chen
Foams can be seen everywhere in human production and life. An uncontrolled foam event usually leads to product losses, equipment damage, and clean-up costs. Defoamer is one of the most effective strategies to eliminate or inhibit foam activities, which has been proved by long-term practices. In this work, we report new molecular defoamers with high-branched structure, which adopts melamine molecule as the parent structure, by incorporating alkyl-isocyanates with different chain lengths into the high-branched melamine derivatives (Hb-MDs) formula to replace the R − NH 2 (primary ammonia) on melamine structure. The substitution reaction processes can be readily tuned by varying the molar ratio or alkyl chain length of alkyl-isocyanate, enabling a facile control over the branched degree. The foam tests reveal that the high-branched melamine molecule defoamers exhibited excellent defoaming and anti-foaming properties for four typical foam systems, including an anionic SDBS , cationic DTAB , non-ionic AEO-9, and white cat (BM) detergent, with efficiency close to that of silicone-type LN1414 defoamer and far superior to that of high-carbon alcohol XS-02 defoamer, at the same addition level. Notably, the defoaming or anti-foaming performances of the high-branched melamine molecule defoamers were not always monotonically increased with the branched degree or hydrophobic chain length, but a suitable range needed to be maintained to support a good balance of defoamer structure with foam liquid films . Therefore, it is anticipated that this high-branched design principle could open a new avenue for the construction of molecular defoamers for complex industrial problems.
研究领域:
化学工程
·
材料科学
·
表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CONTROL
·
2018
·
IF 3.667
Xueqi Leng,Yuqin Tu,Yunping Wu,Yu Wang,Su Liu,Qianqian Pei,Xuejun Cui,Jiadong Huang
A fluorescence sensing strategy was described for the determination of melamine with ultrasensitivity and high specificity. This strategy relies on the combination of proximity ligation assay (PLA)-modulated thymine–melamine–thymine (T–melamine–T) triplex structure along with exonuclease III (Exo III)-aided recycling amplification. The reaction system involves three DNA probes (poly A, tDNA and molecular beacon (MB)). Probe ploy A is an adenine enriched sequence containing an apurinic/apyrimidinic site (AP site). It can provide a hydrophobic vacancy for specially recognizing melamine to bind the nucleobase through pseudo-base pairing and participate in PLA modulated T-melamine-T triplex structure. Probe tDNA can form T-melamine-T with probe poly A via PLA only in the presence of melamine. Probe MB is modified with a fluorophore at its 5′-terminus and a quencher at an internal position, which can self-hybridize to form a hairpin structure, positioning the fluorophore in close proximity to the quencher. Therefore, the binding of MB did not yield any fluorescence signal. However, in the presence of melamine, a T-melamine-T triplex structure is formed through PLA. Probe MB can hybridize with t T-melamine-T triplex structure to yield a substrate for interaction with Exo III. As a result, the T-melamine-T triplex structure is released. Next, the released T-melamine-T triplex structure will hybridize with another MB probe to achieve the Exo III-aided recycle amplification. This is the first example of PLA-modulated T-melamine-T triplex structure coupled with Exo III-aided recycling amplification. Under optimal conditions, the assay has a detection range over 4 orders of magnitude and a limit of detection of 4.4 nM. Moreover, the assay is rapid, simple and inexpensive. Hence, the strategy may open new avenues for ultrasensitive and highly specific detection of melamine encounted in food analysis .
研究领域:
分析化学
·
食品科学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 11
·1557
·
IF 4.7
An Wei,Shunxiang Wang,Yongjin Zou,Cuili Xiang,Fen Xu,Lixian Sun
To broaden the applications of wood, it is necessary to prepare flame-retardant coatings that can protect wood substrates during combustion. In this study, a bio-based, intumescent, flame-retardant phytic acid–melamine polyelectrolyte (PM) was prepared using phosphorus-rich biomass phytic acid and nitrogen-rich melamine as raw materials through an ion crosslinking reaction. Subsequently, a series of bio-based, flame-retardant wood coatings were prepared by optimizing the structure of urea–formaldehyde resin with the addition of melamine, sodium lignosulfonate, and PM as a flame-retardant curing agent. Woods coated with PM-containing coatings displayed significantly improved flame-retardant performances in comparison to uncoated woods. For PM-cured woods, the measured values of total heat release and total smoke production were 91.51% and 57.80% lower, respectively, compared with those of uncoated wood. Furthermore, the fire growth index decreased by 97.32%, indicating a lower fire hazard. This increase in flame retardancy and smoke suppression performance is due to the dense expanded carbon layer formed during the combustion of the coating, which isolates oxygen and heat. In addition, the mechanical properties of the flame-retardant coatings cured with PM are similar to those cured with a commercial curing agent, NH4Cl. In addition, the prepared flame-retardant coating can also stain the wood. This study proves the excellent flame-retarding and curing effect of ammonium phytate in urea–formaldehyde resin coatings and provides a new approach for the application of bio-based flame retardants in wood coatings.
研究领域:
材料科学
·
林业工程
·
生物质化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Ming Wu,Jun-Min Yan,Xue-wei Zhang,Ming Zhao
The g -C 3 N 4 is synthesized by directly heating the acetic acid treatment melamine. A combination of XRD, SEM, TEM, PL and UV–vis are utilized to characterize the composition, morphology and optical properties of g -C 3 N 4 . This method synthesized g -C 3 N 4 shows smaller particles and some holes which high up the photocatalytic activity compared with the bulk g -C 3 N 4 .
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 42
·32897-32901
·
IF 3.84
Miaolin Yin,Lifang Zhao,Qin Wei,He Li
A simple, rapid and sensitive detection method by the naked eye for melamine in dairy products is reported. Within 60 min, melamine can be detected as low as 0.4 μM by UV-vis spectrometric or naked eye observation, which is far below the melamine safety limit in the USA and EU.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Na Li,Ting Liu,Shi Gang Liu,Shu Min Lin,Yu Zhu Fan,Hong Qun Luo,Nian Bing Li
Using carbon dots as the reductant and stabilizer, a visible and fluorescent method was developed for melamine detection in raw milk with one-step synthesized silver nanoparticles. In this work, carbon dots (C-dots) were applied to reduce silver ions and stabilize the nanoparticles, resulting in the formation of silver nanoparticles (AgNPs). As a result, the inherent fluorescence emission of C-dots was significantly reduced after the formation of AgNPs. However, in the presence of melamine, silver ions could interact with the nitrogen atoms in amine and triazine groups of melamine. With 0–2 μM melamine, aggregated AgNPs were found after the reduction by C-dots, resulting in color and absorbance changes. With further increase of melamine (2–20 μM), both formation and aggregation of AgNPs were inhibited, and the fluorescence was gradually increased. This optical platform was optimized for melamine detection and then was applied to detecting melamine in raw milk samples. The results for melamine assay based on visible and fluorescent method showed the requisite sensitivity with a low detection limit of 30 nM, as well as high selectivity.
研究领域:
分析化学
·
食品科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）