Volume 28,Issue 4,2012 Table of Contents

1 Effects of Nitrogen Source on Photosynthesis and Pigment Accumulation of Chlorella sp. TCCC45058

ZHAO Hua , DONG Xiao-yu , XIA Yuan-yuan , NIU Kun

2012, 28(4):367-370.

[Abstract](1171) [HTML](0) [PDF 408.38 K](780)

Abstract:
In the study, effects of four kinds of nitrogen source (carbamide, NH4NO3, (NH4)2SO4 and NaNO3) on biomass, photosynthesis and Chlorophyll A productivity of Chlorella sp. TCCC45058 under autotrophy condition was investigated. The highest cell density (4.1×107/mL) of Chlorella sp. TCCC45058 was acquired when NaNO3 was used as nitrogen source. The optimal nitrogen source for pigment accumulation of Chlorella sp. TCCC45058 was carbamide, with which the highest Chlorophyll A productivity of cell was found as 21 mg/g. Different nitrogen source showed varied influences on medium pH. When NaNO3 was used as nitrogen source, medium pH rose significantly with consuming of NO3-. Use of (NH4)2SO4 as nitrogen source resulted in reduced medium pH. Carbamide and NH4NO3 had little effect on it. When medium pH was controlled at neutral, the result of culture has not improved. Therefore, it was unnecessary to adjust medium pH throughout the cultivation.

2 Effect of Salt Concentration and Storing Temperature on Histamine Formation in the processing of Dried Saury

TAO Zhi-hua , HAN Ya-li , SATO Minoru

2012, 28(4):371-373.

[Abstract](1268) [HTML](0) [PDF 311.58 K](674)

Abstract:
Because fishes are easy to be polluted by histamine-forming bacteria which can grow ddruing the processing of sun-dried saury, producing histamine. Therefore, the effects of salt concentration (5%, 10%, 20%) and temperature (20℃, 25℃) on thehistamine content in the dried saury stored for 6 days were investigated. Results showed that histamine was decreased with lowering the salt concentration. And the histamine content in the dried saruy samples stored at 25℃ was higher than that storted at 20℃.

3 Study on the Properties of Wheat Resistant Starch

WANG Juan , LIU Ze-han , ZHANG Kai , HUANG Ji-hong

2012, 28(4):374-377.

[Abstract](1475) [HTML](0) [PDF 432.60 K](750)

Abstract:
Autoclave processing was applied to prepare wheat resistant starch RS3. The physicochemical and structure properties of product were studied. Results showed that the product contained 13.89% resistant starch. The water-holding capacity, solubility and swelling capacity increased along with increasing the temperature of water bath. The maximum absorption wave of the starch-iodin compound was at 594 nm, and a widen absorption peak in the curve was found between 580~610 nm. Most of the starch granules were rotundity, with strong polarization cross. Moreover the crossing points were in the centre of the granules. The product was hard to gelatinize but easy to retrogress, and the gelatinization temperatures was 68.7 ℃. Crystal type of this starch granule was C-type. The main characteristic peaks of the product in the infra-red spectrum figure are similar to that of the wheat starch.

4 Evaluation and Applications of Inhibitory Effects of Kojic acid and Ferulic acid on Tyrosinase

JIN Yi-qiong , CHEN Zhou-tan , LAI Fu-rao , GIRI Anupam , WU Hui

2012, 28(4):378-381.

[Abstract](1380) [HTML](0) [PDF 353.49 K](728)

Abstract:
Lineweaver-Burk Plot was adopted to investigate the inhibitory effects of kojic acid and ferulic acid on the oxidation of L-DOPA catalyzed by mushroom tyrosinase. The potential mechanism of their inhibitory effects was estimated based on the results obtained from Lineweaver-Burk Plot. The IC50 and inhibitory constant (KI) indicated that the inhibitory effect of kojic acid was considerably higher than that of ferulic acid. In addition, spectrophotography and ImageJ were employed to analyze their preventive effects on browning of shrimp hemolymph and apple slices, respectively. Kojic acid possessed better preventive activity towards browning of shrimp hemlymph; while ferulic acid was more effective than kojic acid in terms of sliced apple browning.

5 Rregulation Effect of Fresh Mangosteen Saponins on Blood Sugar

HE Chao-wen , YAO Mei-cun , XIA Xing , ZHU Xiao-yun , HE Wei-ping

2012, 28(4):382-386.

[Abstract](1661) [HTML](0) [PDF 344.93 K](713)

Abstract:
To study blood sugar regulation effect of Fresh Mangosteen Saponins (FMS), normal mice were orally administrated with FMS for one day or seven days. At 30 min after, intragastric administration with starch, sucrose or glucose respectively, Glycemic index (GI), insulin concentration and inhibition rate of α-glucosidase were determined. Result showed that single dosage of FMS inhibited GI of tarch and sucrose significantly, but had no effect on GI of glucose. After 7 days administration of FMS, GI of both tarch and glucose were inhibited, GI and the peak value of blood glucose are reduced. FMS administration increased postprandial insulin concentration significantly, and FMS dose-dependently inhibited α-glucosidase activity. It was concluded that FMS produced significant inhibition of postprandial blood glucose in normal mice, this effect is mediated primarily by inhibition of food glucose transformation and insulin increasing. When compared with the dry mangosteen saponin, FMS demonstrated higher insulin-increasing effect than dry mangosteen saponin, while the α-glucosidase inhibitory activity was weaker.

6 Synthesis and Antimicrobial Activity of Monobenzyl Fumarate

LIU Qian , WEI Qing-yi , LIU Li-ping , NING Zheng-xiang

2012, 28(4):387-390.

[Abstract](1345) [HTML](0) [PDF 434.37 K](684)

Abstract:
Monobenzyl fumarate was synthesized from benzyl alcohol and maleic anhydride using anhydrous aluminum chloride as the catalyst. The reaction products were structurally identified by means of melting point measurement, Infrared spectrum (IR) and 1H-NMR. The effects of malor ratio reagents, esterification temperature and time, isomerization catalyst, and isomerization catalyst dosage on monobenzyl fumarate yield were studied. Anhydrous aluminum chloride was shown as the best isomerization catalyst and the optimal reaction conditions were determined as follows molar ratio of maleic anhydride to benzyl alcohol (for 2 g anhydrous aluminum chloride) 0.1/0.1, reaction temperature 60 ℃, reaction time 3 h under reflus condition and further reaction time 2 h after adding isomerization catalyst. Under such conditions, the yield of monobenzyl fumarate reached 74.5%. The experiment of antimicrobial activity showed that monobenzyl fumarate exhibited high anticimicrobial activity.

7 Modeling Of Batch Fermentation Kinetics for Glutathione Production

JIA Jian-ping , QIU Juan-ping , ZHOU Yan-gang

2012, 28(4):391-395.

[Abstract](1307) [HTML](0) [PDF 443.80 K](1039)

Abstract:
The fermentation kinetics of glutathione production by Saccharomyces cerevisiae were studied in a batch system. Logistic equation and Luedeking-Piret equation were used to describe the kinetics of the biomass growth, glutathione production and substrate utilization, respectively. A good agreement was found between experimental data and predicted data, which indicated that the models obtained could describe the glutathione production in the batch fermentation process.

8 Inhibition Effect of Glycosaminoglycan from Sanguinolaria acutas on the Growth of Tumor Cells

LIU Qian , FAN Xiu-ping , WU Hong-mian , HU Xue-qiong

2012, 28(4):396-398.

[Abstract](1326) [HTML](0) [PDF 296.99 K](597)

Abstract:
The anti-tumor effect of Glycosaminoglycan from sanguinolaria acutas on Hela cell, CNE-2Z cell and K562 cell in vitro were analyzed by MTT colorimetric method. Results showed that the GAG had anti-tumor activity and the anti-tumor effect of GAG ranged with its concentration. In synergistic inhibition effect of GAG with positive drug (5-Fu) on tumor cells have a simple addition effect or synergistic effect.

9 Study on Antioxidant Activities of Different Varieties of Citrus

HUANG Li-juan , HU Die , ZHANG Ping , NIE Ying-chun

2012, 28(4):399-401.

[Abstract](1054) [HTML](0) [PDF 285.00 K](675)

Abstract:
A method for evaluating antioxidant activities of different varieties of citrus was developed based on the strong inhibition of the antioxidant constituents on the chemiluminescence of luminol-NaClO system，and the antioxidant activities of four kinds of citrus were determined. Antioxidant activities of citrus were evaluated according to IC50. The results showed that all of the tested citrus had good antioxidant activities, among which the sweet orange showed the highest acivity, followed by green tangerine and orange Shatang. And the weakest activity was found with kumquat. The method based on chemiluminescence of luminol-NaClO system was efficient, rapid and can widely used in evaluating the antioxidant activities of varieties of fruits or other food.

10 Effects of Liposomal Vitamin E on Pork Products

LU Yu-Ming , QI Sui-Jian , CHEN Hai-Bin , YAN Yan-Xin , CHEN Ti-Chang , SONG Yu

2012, 28(4):402-404.

[Abstract](1302) [HTML](0) [PDF 345.92 K](660)

Abstract:
Pork products samples subjected to vitamin E liposome or non-liposomal vitamin E treatment and then stored under the temperature of 4 ℃ were prepared. Through the trend analysis of the peroxide value, acid value and TBA value of the pork products samples, it were found that the liposomes vitamin E in pork products have good antioxidation effects. Storage after 10 days, compared with the control, although acid value difference is small, but peroxide value low about 18% and TBA value low about 16%.

11 Preparation of Acrylamide Polyclonal Antibodies

WANG Xiao-xue , LIU Bing , LV Yan-yan , XU Xiao-jing , FANG Guo-zhen , WANG Shuo

2012, 28(4):405-408.

[Abstract](1700) [HTML](0) [PDF 383.27 K](714)

Abstract:
Rabbits were immunized with three kinds of acrylamide artificial antigens which were synthetized via active ester method, then the antibodies with the titer of 1:32000, 1:40000 and 1:8000 were obtained. High specific antibody was produced from acrylamide and 3-mercaptobenzoic acid (3-MBA). The inhibition rate of antibody against acrylamide derivative at the concentration of 1 μg/mL was 80.7%, and there was no cross-reactivity with acrylamide or 3-MBA. The research provided references for the rapid detection for acrylamide in processed food by ELISA method.

12 Capability and Application of PMA-qPCR Method for Monitoring the Ultrasonic Sterilization Rate

LI Cong-cong , YU Yi-gang , QIU Yang , XIAO Xing-long , GUO Yi-dai , WU Hui

2012, 28(4):409-411.

[Abstract](1139) [HTML](0) [PDF 337.28 K](707)

Abstract:
To evaluate the capability of PMA-qPCR method to monitor the sterilization rate of ultrasound, the cultures were treated with ultrasound and then subjected to PMA-qPCR or plate counting. The dates showed that the PMA-qPCR method was quite effective and applicable. Evaluation of the influence of different factors on the sterilization rate showed that the treatment time and the power were the most important parameters at certain temperature and ultrasonic frequency, while the duty ratio showed little influence on the sterilization rate.

13 Optimization of Phosphate Dosages to Promoting Water Holding Capacity of Surimi by Response Surface Methodology

LIU An-jun , WANG Ping , ZHENG Jie , YIN Shi , CHEN Ying , SHANG Xiao-lan

2012, 28(4):412-415.

[Abstract](1276) [HTML](0) [PDF 466.97 K](671)

Abstract:
The effect of phosphates on water holding capacity of carp surimi was studied by response surface methodology. The results showed that the trisodium phosphate, tripolyphosphate, and the interaction between trisodium phosphate and pyrophosphate significantly affected the cooking loss of surimi. And the best dosages of each phosphate was obtained as: trisodium phosphate 0.25 g/kg, tripolyphosphate 1.75 g/kg, pyrophosphate 0.86 g/kg and hexametaphosphate 1.47 g/kg.

14 Study on the Tissue-smashing Extraction Process of Total Paeony Glycoside

LIU Yu-feng , WANG Cheng-cheng , LIU Yang , WANG Yong-jie , LU Xiao-dan , CHEN Li-jiang

2012, 28(4):416-419.

[Abstract](1075) [HTML](0) [PDF 345.35 K](635)

Abstract:
Total paeony glycoside was extracted by tissue-smashing extraction and the extraction conditions were optimized by orthogonal test using the content of total paeony glycoside as main indices. The results showed that the optimum extraction conditions were as follows: liquid-solid ratio 30:1, soaking time 6 h, extraction time 2 minutes and extraction voltage 70 V, under which the total paeony glycoside yield was up to 4.84%.

15 Effects of Bloom and Dosage of Gelatin on the Quality of Gelatin Gummy

WU Xiu-dong , ZHAO Mou-ming , ZHAO Qiang-zhong , MA Hao

2012, 28(4):420-423.

[Abstract](1513) [HTML](0) [PDF 313.54 K](863)

Abstract:
The quality of gelatin gummy was estimated by the texture detection, the incubation test and the sensory evaluation. The effects of bloom and dosage of gelatin on the texture property, anti-distortion rate and sensory evaluation of gelatin gummy were studied. The results showed that improving bloom and dosage of gelatin can greatly increase the hardness and anti-distortion rate and slightly improve elasticity rate of the gummy. In addition, the gummy with high bloom and dosage of gelatin showed better compactness and chewiness. Gelatin gummy had moderate hardness, high elasticity, good heat stability and sensory quality with the best bloom and dosage of gelatin of 220 g and 6.00%, respectively.

16 Development of a Colloidal Gold Immunochromatographic Strip for Rapid Detection of Herbicide Prometryn

LI Ling-ling , ZHANG Lin , NA Yu , SHENG Wei , WANG Shuo

2012, 28(4):424-426.

[Abstract](1188) [HTML](0) [PDF 358.39 K](1002)

Abstract:
The colloidal gold immunochromatographic assay (CGIA) was applied in rapid detection of herbicide prometryn in water samples．Colloidal gold particles were prepared via trisodium citrate method. The CGIA conditions were optimized for high sensitivity. the detection limit of CGIA was 5 ng/mL and the detection process could be completed within 5 min. The river water samples were detected directly by the strip and the limit of detection was 5 ng/mL. The developed immunoassay in this study was a suitable tool for rapid screening residue of prometryn in water samples.

17 Study on the Stability of an Active Lactobacillus Drink without Sucrose

HUANG Xiao-qing , SI Wei-li , ZHANG Duo-min , ZHOU Xue-song , ZENG Jian-xin

2012, 28(4):427-428.

[Abstract](1000) [HTML](0) [PDF 238.31 K](598)

Abstract:
The stability of an active Lactobacillus drink without sucrose was studied in the paper. When the amounts of CMC, Xanthan gum, Konjac gum, Locust bean gum and Gum Arabic were 0.4‰, 0.20‰, 0.20‰, 0.10‰ and 0.12‰ respectively, the product was obtained with the highest stability and good taste.

18 Optimization of Production Technology of Crystal Moon Cake Crust by Response Surface Methodology

PAN Ke-yi , RUI Han-ming , ZHANG Li-yan

2012, 28(4):429-433.

[Abstract](1002) [HTML](0) [PDF 406.45 K](683)

Abstract:
On the base of single factor experiments (acetylated starch, water and oil), through the experimental design of response surface methodology with three factors and three levels based on the principle of Box-Behnken design, the production technology of crystal moon cake crust were studied. The optimal dosages of acetylated starch, water and oil were 58.19 g, 150 g and 20.29 g, respectively. The weight of the products prepared under the optimal conditions reduced by 3.29 g and the hardness improved by 122.38 g.

19 Preparation of Dietary Fiber from Peel of Citrus sinensis Osbeck by Fermentation

WEI Na

2012, 28(4):434-437.

[Abstract](1192) [HTML](0) [PDF 351.11 K](669)

Abstract:
Dietary fiber from peel of Citrus sinensis Osbeck was prepared by fermentation of Trichoderma viride and Rhizopus oryzae. The optimal medium composition was found by single factor and orthogonal design method as follows: Trichoderma viride-Rhizopus oryzae ratio 3:2, fermentation temperature 25 ℃, pH 6.0 and fermentation time 3d. Under the optimal conditions, SDF, IDF and TDF were 32.93%, 49.87% and 82.80%, respectively. The expansibility and water-holding capacity of dietary fiber were 14.5 mL/g and 6.23 g/g, respectively.

20 Extraction of Polysaccharide from Rapana venosa by Orthogonal Test

LIN Hai , HAN Kai-ning , YANG Hong-li

2012, 28(4):438-440.

[Abstract](1368) [HTML](0) [PDF 323.82 K](731)

Abstract:
Extraction conditions for polysaccharide from Rapana venosa were optimized by orthogonal test. The effects of factors, including extraction time, solid to solvent ratio and extraction temperature were investigated using single factor analysis and orthogonal analysis. The results showed that the best conditions for extraction of polysaccharide from Rapana venosa were: extraction temperature 50 ℃; solid to solvent ratio 1:80 (m/V) and extraction time 30 min, under which the polysaccharide yield reached 21.8%.

21 Researches on Anthocyanins of Grape Fruit

WU Bin , ZHANG Yu-li , CHENG Lin-lin , WU Zhong-hong , CHE Feng-bin , WANG Ji-de

2012, 28(4):441-444.

[Abstract](1215) [HTML](0) [PDF 271.75 K](731)

Abstract:
Grape skin contains a large number of physiologically active substances. The majority of which is anthocyanins, proanthocyanidins and phenolic compounds, accounting for 95% polyphenols. In this paper, researches on the grape skin anthocyanins were reviewed, including the types of anthocyanins, structure and properties, the extraction and identification methods.

22 Application of HACCP System in Rice Production

WAN Juan , ZHONG Guo-cai , CHEN wei , WANG Yajun , CHEN Jia-dong

2012, 28(4):445-448.

[Abstract](1432) [HTML](0) [PDF 278.51 K](766)

Abstract:
In order to study the quality control in the production of the rice and improve the safety of the rice, HACCP system was applied for a hazard analysis of the production of rice and the obvious hazards and critical control points were emphasized. For the production of rice, the major hazards were considered as physical, chemical and biological hazards. And the critical control points including the raw materials, storage, rice polishing and product packaging.

23 Investigation and Analysis of Phosphate Residue in Frozen Shrimps and Frozen Shrimp Meat in Qingdao

WANG Ying-ying , ZHANG Hui-zhen , GAO Hua

2012, 28(4):449-451.

[Abstract](1338) [HTML](0) [PDF 312.88 K](1138)

Abstract:
In order to provide scientific basis for the safety and risk assessment of aquatic products, the residue level of phosphates in aquatic products sampled from different market sources of Qingdao was investigated. The concentrations of orthophosphate, pyrophosphate, tripolyphosphate and trimetaphosphate in 265 aquatic products, including 64 samples of frozen shrimps and 201 samples of frozen shrimp meat, were determined by ion chromatography method. The results showed that only a few aquatic products had high orthophosphate concentrations, and the level of pyrophosphate and tripolyphosphate were higher than that of other polyphosphates. No significant differences in orthophosphate concentration in frozen shrimps and frozen shrimp meat were found (P>0.05), but theconcentrations of three kinds of polyphosphates were quite different (P<0.05). The level of polyp hosphates in frozen shrimp meat was higher than frozen shrimps.

24 Determination of Poly(malic acid) in Fermentation Broth by RP-HPLC

QIAO Chang-sheng , JIANG Shao-li , MA Zheng-wang , LI Zheng , LOU Peng

2012, 28(4):453-455.

[Abstract](1438) [HTML](0) [PDF 424.21 K](659)

Abstract:
For the detection of poly (malic acid) fermentation broth, a reversed phase high performance liquid chromatography method was developed. The samples was analyzed on a column of AlltimaTM C18 (4.6 mm×150 mm, 4 μm) with a mixture of acetonitrile and 0.025 mol/L KH2PO4 buffer (pH 2.5) (5:95, v:v) used as mobile phase at the flow rate of 1.0mL/min. The detection wavelength was 210 nm; the column temperature was 25 ℃ and the volum of injection was 5 μL. Before sampling, the fermentation broth was centrifuged to remove fungis, added with organic solvent to remove polysaccharide and hydrolysed. L-malic acid were completely separated and determined in 3 minutes. The recovery and relative standard deviation (RSD, n=3) of L-malic acid by RP-HPLC method were 98.70%~100.65%, and 0.40%~1.11%, respectively. The recovery and relative standard deviation (RSD, n=3) of L-malic acid by L-malic acid kit were 96.70%~97.23% and 0.57%-1.19%, respectively. The method was proved to be a effective way to determine the poly (malic acid) in fermentation broth.

25 Analysis of Volatile Components in Ethanolic Extract of Propolis

TIAN Wen-li , ZHAO Ya-zhou , FANG Xiao-ming , GAO Ling-yu , PENG Wen-jun

2012, 28(4):456-461.

[Abstract](1227) [HTML](0) [PDF 476.47 K](621)

Abstract:
The volatile components in ethanolic extract of propolis (EEP) from China and Malaysia were compared by head space solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrum (GC-MS). As the results, 60 components were found in EEP from China. Curcumene, himachalene, phenylethyl alcohol, phenethyl acetate and cedrene were the major components of EEP from China. 29 components were found in EEP from Malaysia. Benzaldehyde, naphthalene, 2-pentyl furan, 2-methyl naphthalene and copaene were the major components in EEP from Malaysia. The content of volatile components in EEP from China were 10 times than that in EEP from Malaysia. In 2 types of EEP, common components, including ethanol, styrene, cedrene, benzyl alcohol and 4-ethyl-2-methoxy phenol, were found with different concentration.

26 Determination of 24 Metal Elements in Pleurotus eryngii Quei by Inductively Coupled Plasma Mass Spectrometry with Microwave Digestion for Sample Preparation

LUO Xiao-yin , GUO Xin-dong , LIU Hua-chun , YE Jia-rong , GUO Wei-peng , WU Yu-luan

2012, 28(4):462-465.

[Abstract](1187) [HTML](0) [PDF 331.73 K](619)

Abstract:
A method was established to determination of 24 metal elements in Pleurotus eryngii Quei. After microwave digestion, the samples were determined directly by inductively coupled plasma mass spectrometry which used Sc, Ge, Y, In, Tb, Bi as internal standard to correct matrix interference and signal drifting. The quality of the results was proved by the recovery experiments (ranging from 90.1% to 118.9%). The linear correlative coefficient for all elements was higher than 0.999. The relative standard deviations varied from 0.6% to 5.6% (n = 11). The proposed method is fast, simple, sensitive and accurate, which can meet the demand for determining 24 metal elements in Pleurotus eryngii Quei.

27 Determination of Imidaeloprid Pesticide Residue in Fresh Vegetables by HPLC

ZHANG Xue-hui , DU Yu-qian , XU Fang , WANG Qi

2012, 28(4):466-468.

[Abstract](1198) [HTML](0) [PDF 339.10 K](716)

Abstract:
A novel high performance liquid chromatography (HPLC) method was developed for the analysis of imidaeloprid pesticide residue in fresh vegetables. Imidaeloprid was extracted from the samples by acetonitrile, purified with LC-NH2 column and determined by high performance liquid chromatography with UV detection. Symmetry Shield? C18 column (4.6×250 mm, 5 μm) using the mixture of methanol, water and acetonitrile (55:25:20) as the mobile phase. The column temperature, flow rate，detection wavelength and sample volume were 30.0 ℃, 0.8 mL/min, 275 nm and 10.0 μL, respectively. Within the linear range of 0.1~1.0 mg/L, the correlation coefficient, the recoveries of imidaeloprid in tomato and the relative standard deviations (RSD) were 0.9925, 95.4%~106.8 % and 2.66%~7.99%, respectively. The method was simple, effective and accurate. It can be applied to determinate imidaeloprid pesticide residue in fresh vegetables.

28 A Specific Loop-mediated Isothermal Amplification Method for Detection of Transgenic Maize MON89034

ZHANG Jun , LI Zhi-yong , YE Yu-xin , HUANG Yun , LIU Jin , YU Yi-gang , GAO Dong-Wei , SHI Lei

2012, 28(4):469-472.

[Abstract](1239) [HTML](0) [PDF 365.43 K](665)

Abstract:
According to MON89034 exogenous insert sequences connection with the plant genome sequences, the best specific primers were designed, the reaction system and reaction conditions were optimized, and finally a loop-mediated isothermal amplification method for detecting transgenic maize MON89034 was established. Specificity, sensitivity, stability and repeatability of this method were tested. The results showed that the method can specifically detect maize MON89034, and the detection sensitivity of the method was up to 1pg.With the maize MON89034 DNA samples of 1.00%, 0.10%, 0.05% concentration as templates, stability and repeatability testing was conducted, false negative rate was 0. The results showed that the LAMP method is suitable for specifically detecting transgenic maize MON89034.

29 Determination of Isocarbophos in Cowpea by LC/MS/MS with MRM-IDA-EPI

ZOU Shu-dan , HUANG Jin-feng , LUO Dong-hui , LUO Hai-ying , CHEN Li-wei , WU Yu-luan

2012, 28(4):473-475.

[Abstract](1440) [HTML](0) [PDF 392.15 K](766)

Abstract:
An analytical method for the determination of isocarbophos residues in cowpea with HPLC/MS/MS was established. Samples were extracted by acetonitrile with sonic extracting and detected LC/MS/MS. The LODs (S/N=3) were 0.1 μg/kg. For spiking level at 0.1, 1.0, and 5.0 μg/kg, the average recoveries were 80.1%~87.9% and RSD (n=6) values ranged from 6.7% to 8.1%. Using the MRM-IDA-EPI model, MRM chromatograms and the MS2 mass spectrum of the samples can be obtained by only one single injection. The method was simple, precise and had high recoveries, which can meet the requirement for residues analysis.

30 Development of an Indirect Competitive ELISA for Rapid Analysis of Furazolidone Metabolite Residues in Animal Food

LI Min , HE Xiao-wei

2012, 28(4):476-479.

[Abstract](1229) [HTML](0) [PDF 328.27 K](640)

Abstract:
Based on artificial antigen and specific polyclonal antibody, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed to detect 3-amino-2-oxazolidone (AOZ), followed by derivatization with 2-nitrobenzaldehyde. The selection of the optimum concentrations of the coating antigen, the polyclonal antibody and HRP-conjugated antibody was performed by ic-ELISA and square titration. Calibration curve was prepared for NPAOZ (3-(2-Nitrobenzylidenamino)-2-oxazolidinone), a 2-nitrobenzaldehyde derivative of AOZ, and good linearity was achieved over the concentration (0.25-10 ng/mL), the obtained IC50 was between 0.5881 ng/mL and 1.1333 ng/mL. In addition, the antibody was high specific for NPAOZ and no cross-reactivity with analog. The accuracy of the assay was validated by determining the recovery in shrimp tissue. High temperature and short time derivative process can be in line with incubating at 37 ℃ overnight.

31 Study of methods for Sucralose Determination in Wine

LONG Fei , DING Yi , LONG Yan-jun

2012, 28(4):480-482.

[Abstract](1361) [HTML](0) [PDF 287.53 K](691)

Abstract:
In this paper, two methods based on HPLC-DAD and HPLC-RID was tested for detection of sucralose in wine. The repeatability, accuracy and detection limits of the two method were compared with HPLC-ELSD in national standard. It was found that the two methods can be used as alternative to national standard. The detection limits of the two methods were 6.0 mg/L and 1.7 mg/L, respectively.

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Volume 28,Issue 4,2012 Table of Contents