Determination of Residual Acrylamide Monomer in Medical Polyacrylamide Hydrogel by HPLC-SPE

2005 ◽  
Vol 288-289 ◽  
pp. 405-408
Author(s):  
Zi Yi Wan ◽  
Ting Fei Xi ◽  
P. Zhao ◽  
Y. Sun ◽  
Z.G. Feng
Keyword(s):  
Detection Limit ◽  
Solid Phase ◽  
Polyacrylamide Hydrogel ◽  
Simple Method ◽  
Lower Detection Limit ◽  
Response Range ◽  
Coefficients Of Variation ◽  
Lower Detection ◽  
Linear Response Range

The polyacrylamide hydrogel (PAMG) has been used in cosmetology in China, Ukraine and Russia since 1990s. Because the monomer acrylamide(AM) used to produce PAMG has been implicated as a potential mutagen and reproductive toxicant[1,2], it is important to accurately determine the amount of residual AM monomer in the PAMG. In this study, a quick, practical and simple method to determine AM is presented with respect to the hydrogel. AM is analysed quantitatively by ODS-3 column with ultraviolet (UV) absorbance detector. AM is separated from interferential component with an aqueous solution of 0.9%NaCl (NS) adjusted at pH~3.7 using hydrochloric acid and then detected at a UV wavelength of 210 nm. The results show that ODS-3 is effective approach for quantifying AM concentrations in PAMG. This method has a lower detection limit of 0.003µg/ml and a linear response range of 0.003 and 0.9 µg/ml (depending on the range required for analysis). Precision studies give coefficients of variation of <3.2%(n=5) for 0.003µg/ml. The recoveries for this method are greater than 90%. When AM content in PAMG is lower than the detection limit of this method, SPE (solid phase extraction) could be used to concentrate AM. In the case, C18 cartridge is used. And the recoveries are about 70% for SPE when AM concentration is lower than ppb.

Direct solid-phase enzymoimmunoassay of testosterone in saliva.

1989 ◽  
Vol 35 (10) ◽  
pp. 2044-2047 ◽  
Author(s):  
K Howard ◽  
M Kane ◽  
A Madden ◽  
J P Gosling ◽  
P F Fottrell
Keyword(s):  
Detection Limit ◽  
Analytical Procedure ◽  
Solid Phase ◽  
Medical Applications ◽  
Microtiter Plates ◽  
Large Numbers ◽  
Coefficients Of Variation ◽  
Serial Sampling ◽  
Direct Solid

Abstract This competitive, solid-phase enzymoimmunoassay for testosterone in saliva is carried out on microtiter plates and involves no chromatographic or extraction steps. With an overnight incubation the detection limit of the assay is 230 fg per well (16.1 pmol/L). There was a good correlation (correlation coefficient 0.95) between testosterone concentrations measured with and without prior extraction of the saliva samples. Repeated assay of three control saliva samples containing a range of testosterone concentrations (200-1000 pmol/L) gave within- and between-assay coefficients of variation of 5.5-13.2%. The analytical procedure is simple and closely resembles already published procedures for the determination of progesterone and estrone (with extraction) in saliva. One person can assay 200 samples in 24 h and the assay is suitable for reproductive and sports medical applications, particularly for projects involving serial sampling and yielding large numbers of samples.

Improved Spectrophotometric Determination of Cyclopiazonic Acid in Poultry Feed and Corn

1990 ◽  
Vol 73 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Ivan Chang-Yen ◽  
Keshore Bidasee
Keyword(s):  
Detection Limit ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Cyclopiazonic Acid ◽  
Poultry Feed ◽  
Reaction Conditions ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Feed Samples

Abstract An improved visible spectrophotometric method has been developed for cyclopiazonic acid in poultry feed and corn. The method Is based on the reaction of cyclopiazonic acid with Ehrlich reagent and detection at 580 nm. Reaction conditions were optimized with respect to reaction and measurement times and acid and Ehrlich reagent concentrations. Calibration curves were linear from 1 to 20 μg cyclopiazonic acid in 3 mL Ehrlich reagent, with a lower detection limit of 0.08 mg/kg for 50 g samples of poultry feed and corn. Recoveries from 50 g samples of poultry feed spiked with cyclopiazonic ranging from 0.16 to 1.20 mg/kg averaged 93.8%. Moldy corn and poultry feed samples analyzed by this method contained between 1 and 4 mg/kg cyclopiazonic acid.

Determination of glutathione and glutathione disulfide in human whole blood using HPLC with coulometric detection: A comparison with fluorescence detection

2011 ◽  
Vol 76 (4) ◽  
pp. 277-294 ◽  
Author(s):  
Roman Kanďár ◽  
Pavla Žáková ◽  
Miroslava Marková ◽  
Halka Lotková ◽  
Otto Kučera ◽  
...  
Keyword(s):  
Detection Limit ◽  
Whole Blood ◽  
Trichloroacetic Acid ◽  
Signal To Noise Ratio ◽  
Glutathione Disulfide ◽  
Simple Method ◽  
Human Whole Blood ◽  
Coulometric Detection ◽  
Coefficients Of Variation

We describe a relatively simple method for the determination of glutathione (GSH) and glutathione disulfide (GSSG) in human whole blood. We have used an HPLC with coulometric electrochemical detection for the simultaneous measurement of GSH and GSSG. Diluted and filtered trichloroacetic acid extracts were injected directly into the HPLC system and were eluted isocratically on a Polaris 5u C18-A, 250 × 4.6 mm analytical column. Glutathione in samples extracted with trichloroacetic acid and diluted with 1.0 mMhydrochloric acid was stable at 4 °C for at least 8 h. The analytical performance of this method is satisfactory: the intra-assay and inter-assay coefficients of variation were below 10%. Quantitative recoveries from spiked whole blood samples were at intervals 91.6–97.6% for GSH and 85.0–104.4% for GSSG. The linear range is 5.0–2000.0 μmol/l, with a detection limit of 2.1 μmol/l (signal-to-noise ratio = 3) for GSH and 2.0–250.0 μmol/l, with a detection limit of 0.9 μmol/l for GSSG.

scholarly journals Determination of epinephrine by the Briggs-Rauscher oscillating system using non-equilibrium stationary state

2012 ◽  
Vol 77 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Jinzhang Gao ◽  
Yanjun Liu ◽  
Jie Ren ◽  
Xiaoli Zhang ◽  
Li Ming ◽  
...  
Keyword(s):  
Detection Limit ◽  
Stationary State ◽  
Lower Detection Limit ◽  
Highly Sensitive ◽  
Lower Detection ◽  
Oscillating Reaction ◽  
The Difference ◽  
Foreign Species ◽  
Non Equilibrium

A highly sensitive method for the determination of epinephrine was proposed, which was based on the perturbation of epinephrine to Briggs-Rauscher oscillating system involving malonic acid, Mn2+, H+, IO3 - and H2O2 at non-equilibrium stationary state. The concentration of KIO3 was chosen as a control parameter to find the bifurcation point in this paper. Results showed that a well linear relationship between the difference of potential and the negative logarithm concentrations of epinephrine existed in the range of 1.1?10-7?5.2?10-9 mol L-1 with a lower detection limit of 6.8?10-10mol L-1 and a correlation coefficient of 0.9974. Compared to the classical oscillating reaction, this method has a lower detection limit and wider linear range. The effects of some foreign species, which may possibly be existed with epinephrine, on determination were also investigated. The proposed method has been successfully used to determine the epinephrine both in the serum and adrenaline hydrochloride injection.

Analysis of Tri-aryl Phosphate Esters and the Determination of Imol S-140 in Fish Tissue and Water Samples by Gas Chromatography

1975 ◽  
Vol 32 (4) ◽  
pp. 457-460 ◽  
Author(s):  
Derek A. J. Murray
Keyword(s):  
Gas Chromatography ◽  
Detection Limit ◽  
Water Samples ◽  
Fish Tissue ◽  
Phosphate Esters ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Trimethylsilyl Derivatives ◽  
The Individual

This report describes a method for the analysis of tri-aryl phosphate esters used commercially as lubricants. In a fish toxicity study, Imol S-140 (tri-tolyl phosphate) was extracted from fish tissue and water samples, hydrolyzed, and the individual phenols measured by gas chromatography as the trimethylsilyl derivatives. The lower detection limit was about 3 ppm of Imol in wet fish tissue.

Differential assay of zidovudine and its glucuronide metabolite in serum and urine with a radioimmunoassay kit

1990 ◽  
Vol 36 (6) ◽  
pp. 897-900 ◽  
Author(s):  
S M Tadepalli ◽  
L Puckett ◽  
S Jeal ◽  
L Kanics ◽  
R P Quinn
Keyword(s):  
Inhibitory Concentration ◽  
Serum Samples ◽  
Lower Detection Limit ◽  
Coefficients Of Variation ◽  
Lower Detection ◽  
Before And After ◽  
The Difference ◽  
Glucuronide Metabolite ◽  
Serum And Urine

Abstract We developed an ancillary procedure for the ZDV-Trac RIA (Incstar) to allow simultaneous determination of both zidovudine (3'-azido-3'-deoxythymidine, ZDV, AZT, Retrovir) and its metabolite, the glucuronide of ZDV (3'-azido-3'-deoxy-5'-O-beta-D-glucopyranuronosylthymidine, ZDVG, GAZT), in human serum and urine. Using the ZDV-Trac RIA, we measured ZDV concentrations before and after ZDVG in samples was hydrolyzed to ZDV by beta-glucuronidase (EC 3.2.1.31); ZDVG concentration was calculated as the difference between the two results. This method enables rapid evaluation of a large number of samples with a total turn-around time of 6 h. The lower detection limit of the RIA was 0.27 micrograms/L; the measurements varied linearly with ZDV concentrations from 0.27 to 217 micrograms/L, with the 50% inhibitory concentration being approximately 10 micrograms/L. Analytical recoveries of inhouse serum and urine controls for both ZDV and ZDVG exceeded 90%. Coefficients of variation (CVs) of serum controls were less than 6% for ZDV and less than 11% for ZDVG; for urine controls, CVs for both ZDV and ZDVG were less than 6%. Results for ZDVG concentrations obtained by HPLC and by the ZDV-Trac RIA system compared well: r = 0.978, slope 1.0, for serum samples, and r = 0.993, slope 1.09, for urine samples.

scholarly journals Determination of p-nitroaniline by the tartrate-acetone-Mn2+-KBrO3-H2SO4 double organic substrate oscillating system using non-equilibrium stationary state

2009 ◽  
Vol 7 (3) ◽  
pp. 298-302 ◽  
Author(s):  
Jinzhang Gao ◽  
Jing Liu ◽  
Jie Ren ◽  
Xiuli Niu ◽  
Yingying Zhang ◽  
...  
Keyword(s):  
Detection Limit ◽  
Linear Relationship ◽  
Bifurcation Point ◽  
Convenient Method ◽  
Control Parameter ◽  
Organic Substrate ◽  
Optimum Conditions ◽  
Lower Detection Limit ◽  
Lower Detection

AbstractThis paper described the determination of p-nitroaniline in a double organic substrate oscillating system of tartrate-acetone-Mn2+-KBrO3-H2SO4. Under the optimum conditions, temperature was chosen as a control parameter to design the bifurcation point and proposed a convenient method for determination of p-nitroaniline. Results showed that the system consisting of 3.5 mL 0.06 mol L−1 tartrate, 4.0 mL 0.7 mol L−1 H2SO4, 1.5 mL 1.5×10−4 mol L−1 MnSO4, 4.0 mL 0.4 mol L−1 acetone and 7.0 mL 0.05 mol L−1 KBrO3 was very sensitive to the surrounding at 33.5°C. A good linear relationship between the potential difference and the negative logarithm concentration of p-nitroaniline was obtained to be in the range of 2.50×10−7∼3.75×10−5 mol L−1 with a lower detection limit of 2.50×10−8 mol L−1.

scholarly journals Liquid ChromatographicDiode-Array Detection Multiresidue Determination of Rice Herbicides in Drinking and Paddy-Field Water

2009 ◽  
Vol 92 (4) ◽  
pp. 1190-1195 ◽  
Author(s):  
Rafael Roehrs ◽  
Renato Zanella ◽  
Ionara Pizzuti ◽  
Martha B Adaime ◽  
Luca Pareja ◽  
...  
Keyword(s):  
Paddy Field ◽  
Solid Phase ◽  
Diode Array ◽  
Diode Array Detection ◽  
Lower Detection Limit ◽  
Lower Detection ◽  
Array Detection ◽  
Multiresidue Determination ◽  
Postemergence Herbicides

Abstract A sensitive, rapid, and simple multiresidue method for the simultaneous determination of six postemergence herbicides currently used in rice cultivationmetsulfuron methyl, bensulfuron methyl, pyrazosulfuron ethyl, bentazone, bispyribac sodium, and cyhalofop butylin drinking and paddy-field water is presented. Water samples were extracted with solid-phase extraction cartridges. Final determination was made by LC with diode-array detection. The extraction efficiencies of C18 and HLB cartridges were compared. The average recovery obtained for these compounds for the lowest spiked level (0.1 g/L) varied from 70 to 122 for C18 and 75119 for HLB, with RSDs of 11 and 8.3, respectively. The method had good linearity, and the lower detection limit for the pesticides studied varied from 0.03 to 0.04 g/L. The proposed method was also tested in paddy-field water, with recovery studies giving good results with low RSDs at 1.0 g/L.

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