An Automated Method for the Determination of Serum Calcium with Glyoxal Bis (2-Hydroxyanil)

1967 ◽  
Vol 13 (6) ◽  
pp. 515-520 ◽  
Author(s):  
Genevieve Farese ◽  
Janice L Schmidt ◽  
Milton Mager
Keyword(s):  
Serum Calcium ◽  
Automated Analysis ◽  
Automated Method ◽  
Good Agreement

Abstract A completely automated analysis is described for the determination of serum calcium with glyoxal bis (2-hydroxyanil) solution (GBHA). The method is simple and precise, and the data obtained are in good agreement with results obtained by the manual GBHA procedure.

Automated Method for the Analysis of Riboflavin in Milk, with Application to Other Selected Foods

1974 ◽  
Vol 57 (5) ◽  
pp. 1085-1088
Author(s):  
James R Kirk
Keyword(s):  
Standard Deviation ◽  
Continuous Flow ◽  
Quantitative Method ◽  
Green Fluorescence ◽  
Internal Standards ◽  
Automated Method ◽  
Sodium Hydrosulfite ◽  
Automated Technique ◽  
Good Agreement

Abstract A continuous flow automated technique was developed for the determination of riboflavin in milk. The determination is based on the measurement of the natural yellow-green fluorescence of riboflavin at an excitation of 436 nm and emission of 510 nm. Blank values are determined for each sample after sodium hydrosulfite reduction of the riboflavin. Mean recovery and standard deviation for riboflavin in milk determined by the continuous flow procedure using internal standards were 9 7% and ± 2.42%, respectively. The recovery value was in good agreement with that determined using a manual procedure, while the standard deviation was 33% less than that found when using the manual procedure. The results from this study indicate that the continuous flow automated procedure for the determination of riboflavin in milk is a simple, quantitative method which eliminates many of the time-consuming analytical steps.

Collaborative Study of an Automated Method for the Determination of Crude Protein in Animal Feeds

1976 ◽  
Vol 59 (1) ◽  
pp. 141-147
Author(s):  
Rodney J Noel
Keyword(s):  
Crude Protein ◽  
Primary Standard ◽  
Collaborative Study ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Animal Feeds ◽  
Automated Method ◽  
Kjeldahl Method ◽  
Good Agreement

Abstract An automated macro Kjeldahl instrument determines per cent protein at the rate of 20 samples/hr. The methodology involved is similar to the present official final action Kjeldahl method, sec. 7.016. The 2 methods were compared in a collaborative study. Sixteen animal feeds, 4 meats, tryptophan, ammonium dihydrogen phosphate NBS standard, and ammonium sulfate primary standard were analyzed by the participating laboratories. The data were treated statistically and the results showed good agreement between the 2 methods. The automated method has been adopted as official first action for the determination of crude protein in feeds, plants, and cereal foods.

Automated Enzymatic Determination of L-Lysine in Grain

1974 ◽  
Vol 57 (5) ◽  
pp. 1098-1103 ◽  
Author(s):  
Larry L Wall ◽  
Charles W Gehrke
Keyword(s):  
Carbon Dioxide ◽  
Free Water ◽  
Dialysis Membrane ◽  
Standard Curve ◽  
Carbon Dioxide Gas ◽  
Automated Method ◽  
Enzymatic Determination ◽  
Exchange Data ◽  
Good Agreement

Abstract An accurate and precise automated method has been developed for the determination of lysine in grain hydrolysates. The enzyme L-lysine decarboxylase specifically catalyzes removal of the carboxyl group from L-lysine, producing an amine and carbon dioxide. This reaction has been automated. The carbon dioxide produced was selectively dialyzed into a stream of carbonate with phenolphthalein by a dialysis block containing a carbon dioxide gas dialysis membrane. Ground samples of grain (250 mg) were hydrolyzed 20 hr in 25 ml 6N HC1 at 110°C Aliquots were evaporated to dryness under nitrogen with low heat. The samples were redissolved in carbon dioxide-free water and the enzyme was suspended in pH 6.5 phosphate buffer. Analyses were made at 30/hr with a sample-to-wash ratio of 4:1. A standard curve with a range of 0 to 90 ppm lysine was expanded to full scale on the recorder. From the comparative height of each sample peak vs. the standard curve, the per cent lysine in the original sample can be calculated. Repeated analyses on 15 samples, 5 each of corn, mungbeans, and soybeans, by the automated method showed that the precision was good, and the results were in good agreement with classical ion exchange data. The automated method for lysine in corn has been used in our laboratory to analyze 1500–2000 corn samples each year for the last 5 years.

scholarly journals Automated Method for Cleanup and Determination of Benomyl and Thiabendazole in Table-Ready Foods

1998 ◽  
Vol 81 (6) ◽  
pp. 1217-1223 ◽  
Author(s):  
Robert A Levine ◽  
Ronald G Luchtefeld ◽  
Marvin L Hopper ◽  
Garrett D Salmon
Keyword(s):  
Methylene Chloride ◽  
Solid Phase ◽  
Strong Cation Exchange ◽  
Automated Method ◽  
On Line ◽  
Diet Study ◽  
Spe Method ◽  
Liquid Chromatographic ◽  
Good Agreement

Abstract An automated solid-phase extraction (SPE) cleanup with on-line liquid chromatographic (LC) analysis was developed to determine residues of benomyl (as carbendazim) and thiabendazole in table- ready food items from the U.S. Food and Drug Administration Total Diet Study (TDS). A strong-cation- exchange cleanup of an acetone extract replaces the methylene chloride solvent partitioning steps in the procedure described in the Pesticide Analytical Manual(PAM). LC analysis is accomplished with a Cs analytical column and tandem fluorescence and UV detection. Recoveries of both analytes from 32 representative TDS foods fortified at 0.05 and 0.5 μg/g were determined. Method precision was evaluated with triplicate recovery assays on 11 foods fortified at both levels. Accuracy was tested further by assaying 47 foods for incurred residues in parallel with the validated PAM procedure for comparison, and good agreement was found. The automated SPE method reduces solvent consumption, analysis time, and labor.

Determination of Serum Calcium by Automated Atomic Absorption Spectroscopy

1967 ◽  
Vol 13 (5) ◽  
pp. 388-396 ◽  
Author(s):  
Bernard Klein ◽  
James H Kaufman ◽  
Stanley Morgenstern
Keyword(s):  
Hydrochloric Acid ◽  
Atomic Absorption ◽  
Serum Calcium ◽  
Flow System ◽  
Atomic Absorption Spectrophotometry ◽  
Absorption Spectrophotometry ◽  
Comparison Of The Results ◽  
Automated Determination ◽  
Good Agreement

Abstract A procedure is presented for the automated determination of serum calcium by atomic absorption spectrophotometry. The serum sample, diluted with acidified lanthanum dichloride, is dialyzed against 0.1 N hydrochloric acid and a portion of the recipient solution is pumped into the atomizer-burner of the spectrophotometer. Data are presented on the precision and reproducibility of the flow system. Addition of calcium to serum shows a mean recovery of 99%. A comparison of the results of analyses on random specimens by permanganate titration and the automated procedure shows good agreement.

Automated Fluorometric Method For The Determination of Serum Calcium

1969 ◽  
Vol 15 (9) ◽  
pp. 870-878 ◽  
Author(s):  
Benjamin Fingerhut ◽  
Alfred Poock ◽  
Henry Miller
Keyword(s):  
Standard Deviation ◽  
Serum Calcium ◽  
Fluorometric Method ◽  
Good Agreement

Abstract An automated fluorometric procedure for serum calcium has been developed which can be used for a wider variety of pathologic serums than the automated fluorometric and colorimetric technics generally being used at present. The method is based upon measurement of the fluorescence produced by calcein with calcium in a serum dialysate. Results are in good agreement with the Clark-Collip procedure. Recovery experiments averaged 98-101%. The standard deviation for duplicate determinations averaged ±0.20 mg/100 ml.

A Study of Factors Influencing Continuous Flow Kinetics: The Use of Serum Calcium Estimation as a Model

1976 ◽  
Vol 13 (1-6) ◽  
pp. 438-448 ◽  
Author(s):  
Kevin Spencer
Keyword(s):  
Serum Calcium ◽  
Continuous Flow ◽  
Flow Cell ◽  
Peak Shape ◽  
Colour Reaction ◽  
Time Constants ◽  
Automated Method ◽  
Factors Influencing ◽  
Carry Over

Previous studies of continuous flow kinetics have described an “AutoAnalyzer” peak in terms of two time constants, lag constant “a” and exponential constant “b”. Further investigations described here define some of the factors which affect these constants and hence peak shape and analytical performance. This communication outlines the application of this information to the development of an automated method for the determination of serum calcium, having a carry-over of less than 1 % and an analytical rate greater than 100/hour. The instaneous colour reaction, simple hydraulics, removal of the dialysis step, and the use of an integral debubbling flow cell have enabled small kinetic constants to be achieved. Over a period of three months' routine use between-batch coefficient of variation (C.V.) was 1.4%.

Automated Analysis of Vitamin C in Pharmaceutical Products

1975 ◽  
Vol 58 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Omer Pelletier ◽  
Rene Brassard
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Pharmaceutical Preparations ◽  
Automated Analysis ◽  
Pharmaceutical Products ◽  
Copper Salts ◽  
Total Vitamin ◽  
Automated Method

Abstract The determination of total vitamin C in the form of both L-ascorbic acid (AA) and dehydroascorbic acid (DHAA) present in pharmaceutical preparations has been automated. Total vitamin C (completely oxidized to DHAA) was determined by reaction with 2,4-dinitrophenylhydrazine while blanks utilized the same reagent after reducing all DHAA to AA. The automated method was applicable to a variety of multivitamin preparations including those containing iron and copper. The mean recovery of L-ascorbic acid added to 11 multivitamin preparations was 99.4% with a coefficient of variation of 2.5%. In the analysis of these products, results obtained by the automated method were essentially the same as those obtained by the original manual method. For preparations containing no copper salts, the results were also comparable to those obtained by titration with 2,6-dichloroindophenoI except in 1 product which contained some DHAA.

Automated Method for Determination of Serum Calcium by Use of Alizarin

1970 ◽  
Vol 16 (10) ◽  
pp. 816-819 ◽  
Author(s):  
Christopher S Frings ◽  
Patricia S Cohen ◽  
Lowell B Foster
Keyword(s):  
Atomic Absorption ◽  
Serum Calcium ◽  
Coefficient Of Variation ◽  
Atomic Absorption Spectrophotometry ◽  
Manual Method ◽  
Absorption Spectrophotometry ◽  
Automated Method ◽  
Beer's Law ◽  
Beer’S Law

Abstract An automated method is described for determining serum calcium by measuring the red chromogenic complex formed by calcium and alizarin. About 40 µl of undialyzed serum is added directly to one reagent to pro-duce the color, which follows Beer's law at 599 nm to a concentration of 15.0 mg of calcium per 100 ml, with a coefficient of variation of 2.5%. Serum calcium concentrations, as measured by our method, compare favorably with those by the corresponding manual method and by atomic absorption spectrophotometry

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