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Objective To evaluate the measurement uncertainty of the detecting procedure of amino acids and carnitines by the Waters ACQUITY TQD tandem mass spectrometer and PerkinElmer NeoBaseTM non‐derivatized MSMS kit ,and to discuss the meaning of evaluation .Methods According to the method provided by the Medical Laboratories‐Evaluation and Expression of Measurement Uncertainty ,the internal quality control was detected by using two different batch codes of kit for 20 d ,once before and after the routine sample detection on each working day ,the detector were randomly changed ,and then the measurement uncer‐tainty introduced by measurement reproducibility was calculated;the amino acid external assessment quality control data in 20 times of neonatal hereditary metabolic disease tandem mass spectrometry screening provided by the National Center for Clinical Laborato‐ry in 2014 and 2015 ,and the same and 16 times of carnitines external assessment quality control data were performed the statistics , and then the measurement uncertainty introduced by bias was calculated .Next the relative standard uncertainty and the relative ex‐panded uncertainty according to the measurement uncertainty introduced by bias and measurement reproducibility were calculated . The allowed total error indicators of amino acid and carnitines external quality assessment in the neonatal hereditary metabolic dis‐ease tandem mass spectrometry screening by the National Center for Clinical Laboratory were used as the target expanded uncer‐tainty .Results The relative expanded uncertainties of citrulline ,methionine ,phenylalanine ,propionyl carnitine ,octanoyl carnitine , dodecanoyl carnitine ,palmitoyl carnitine and octadecanoyl carnitine were 19 .1% -26 .1% (k=2) ,which were smaller than the tar‐get uncertainty .The relative expanded uncertainties of leucine ,tyrosine ,valine ,free carnitine were 31 .0% -43 .3% (k=2) ,which were greater than the target uncertainty .The uncertainty of isovaleryl carnitine needed to be estimated separately .Conclusion As‐sessing the measurement uncertainty of the detecting procedure of amino acids and carnitines by the non‐derivatized tandem mass spectrometer method can not only provide an opportunity for continuously improving the detection quality ,but also can help the ex‐perimental technique staffs to interpret the test data correctly and the clinician to use the detection reports correctly .
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BACKGROUND: How to control the diameter and distribution of void is a tough problem for the preparation of polyvinylacetate porous materials, which is lack of efficient solutions. OBJECTIVE: To prepare polyvinylacetate porous materials by using high internal phase emulsions as templates, and to study the effect of preparation technique on diameter and distribution of void. DESIGN, TIME AND SETTING: The observational experiment was performed at the Institute of Chemistry and Chemical Engineering, Taishan Medical University from March 2007 to October 2008. MATERIALS: Vinylacetate was supplied by Tianjin Yongda Chemical Industry Co., Ltd. Divinylbenzene and sorbitan monooleate (SPAN 80) were provided by Aldrich Company (USA). Anhydrous calcium chloride and chlorobenzene was obtained from Shanghai No.1 Reagent Plant. Toluene was purchased from Tianjin Zonghengxing Chemical Industry Co., Ltd. 1,2-Dichlorobenzene was offered by Beijing Jingyi Chemical Plant. METHODS: The emulsions were obtained by adding dropwise aqueous solution of CaCl2 and potassium persulfate to the continuous phase (vinylacetate, DVB and Span80) under stirring, and then polymerization was heating by water bath in constant temperature (60 ℃). The solid foams were cut into 1 cm disciform strips and extracted with propanol for 48 hours in a Soxhlet apparatus. Solid foams were dried under vacuum at 50 ℃ to obtain polyvinylacetate porous materials. The void diameter, window diameter was observed by scanning electron microscope, the specific surface area was measured by 3H-2000Ⅱ instrument. MAIN OUTCOME MEASURES: The specific surface area, void diameter and window diameter of porous materials. RESULTS: The void diameters of the polyvinylacetate porous materials were controlled 3.3-5.2 μm with window diameters of 1.7-2.3 μm. The surface areas greater than 720 m2/g could be achieved by replacing some of the monomer phase with non-polymerizable solvent, such as toluene.CONCLUSION: Polyvinylacetate porous materials with tailored void diameters can be produced via optimizing the composition and processing conditions of the emulsion precursor by high internal phase ratio template method.
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OBJECTIVE: To explore effects of various inert solvents on surface morphology and specific surface area of porous materials. METHODS: Span80 served as emulsifier, and toluene, 1,2-dichlorobenzene, 2chloroethyl/benzene and 1-chloro-3-phenylpropane as inert solvent. High internal phase emulsion as template was used to prepare porous polystyrene material. Scanning electron microscope was utilized to observe morphology of porous materials to determine the diameter of foam hole. Nitrogen absorption specific surface area equipment was applied to determine specific surface area of the porous material. RESULTS: The inert solvent had an influence on the structure of the porous materials as follows: the higher compatibility of the inert solvent with styrene, the higher surface area of the solid foam; monomers with higher surface activity tended to penetrate between the chains of a surfactant monolayer to a larger degree, creating a wedge effect on the oil side of the monolayer; the high polarity of the solvent, the greater its ability to incorporate increasing larger quantities of water. Thus, the stability of the emulsions decreased. CONCLUSION: Compatibility of inert solvent and styrene and polarity of inert solvent mainly affect the specific surface area of the porous material. Interface activity of the inert solvent mainly influences foam hole and window size of the porous material.
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Four compounds were isolated from the ethanolic extract of the bark of Alseodaphnehainanensis Merr. , The structures were identified as: a neolignan eusiderin A [(7R, 8R)-3,4,5,3′-tetram-ethox-△8’，9’-8-o-4’，7-o-5’lignan]（I）two benzylisoquinoline alkaloids (6,7-dimethoxyisoquinolinyl)-(4′-methoxyphenyl) methanone(Ⅱ), and( 6, 7-methylenedioxyisoquinolinyl )-( 4′-methoxyphenyl ) methanone (Ⅲ), and 4-hydroxy-3-methoxy benzoic acid ( Ⅳ ) on the basis of HR-SIMS，1HNMR，13CNMRand 2D-NMR spectroscopic analysis. CompoundsⅠ～Ⅲ were obtained from the Alseodaphne genus forthe first time.