Automated Determination of Thiamine (Vitamin B1) in Pharmaceutical Preparations

1971 ◽  
Vol 54 (5) ◽  
pp. 1164-1167
Author(s):  
Omer Pelletier ◽  
RenÉ Brassard
Keyword(s):  
Liver Extract ◽  
Vitamin B1 ◽  
Pharmaceutical Preparations ◽  
Manual Method ◽  
Automated Method ◽  
Thiamine Content ◽  
Aoac Method ◽  
Automated Determination

Abstract The chemical principles used for the determination of thiamine in pharmaceutical preparations by the official USP and AOAC methods were adapted to an automated flowthrough analyzer. The system could analyze 20 samples (including blanks) per hour. Thiamine extracts from 12 different multivitamin preparations were analyzed by one analyst on 5 different days by the automated method and the AOAC method. Both methods yielded comparable values for 10 of the preparations. The thiamine content of 2 preparations containing liver extract was found to be about 9% higher by the automated method than by the AOAC method. Further analysis of other samples of these 2 preparations containing liver extract showed that chromatography on Decalso did not change the results obtained by the automated method, but raised the results obtained by the manual method to a level comparable to the automated method. The AOAC method showed a tendency for a slightly higher reproducibility of assays.

Automated Determination of Serum Ceruloplasmin Activity with o-Dianisidine Dihydrochloride as Substrate

1975 ◽  
Vol 21 (6) ◽  
pp. 757-759 ◽  
Author(s):  
Karl H Schosinsky ◽  
Peter Lehmann ◽  
Myrton F Beeler
Keyword(s):  
Coefficient Of Variation ◽  
Serum Ceruloplasmin ◽  
Manual Method ◽  
Automated Method ◽  
Enzymatic Determination ◽  
Ceruloplasmin Activity ◽  
Automated Determination

Abstract An automated method for the enzymatic determination of ceruloplasmin with o-dianisidine dihydrochioride as substrate is described. The method enables the measurement of 30 samples per hour with a coefficient of variation (day-to-day) of 2.8%. Results correlate well (r = 0.99) with those obtained by the corresponding manual method.

Automated Determination of Free Amino Groups in Serum and Plasma Using 2,4,6-Trinitrobenzene Sulfonate

1969 ◽  
Vol 15 (9) ◽  
pp. 891-901 ◽  
Author(s):  
D W Palmer ◽  
T Peters
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Clinical Applications ◽  
Amino Groups ◽  
Automated Method ◽  
Total Free Amino Acids ◽  
Colored Complexes ◽  
Automated Determination

Abstract A simple automated method is described for determining the level of total free amino acids in the blood. The method utilizes the AutoAnalyzer, and is based on the formation of colored complexes by uniting free amino groups with 2,4,6-trinitrobenzene sulfonate (TNBS). Proteins do not interfere because the free amino acids are first separated by dialysis. Characteristics of the reaction and potential clinical applications of the procedure are discussed.

An Automated Method for the Determination of Estrogens in Pregnancy

1968 ◽  
Vol 14 (10) ◽  
pp. 1010-1022 ◽  
Author(s):  
D Ua Conaill ◽  
G G Muir
Keyword(s):  
Turnover Rate ◽  
Good Recovery ◽  
Manual Method ◽  
Color Development ◽  
Automated Method ◽  
Combined Operation ◽  
In Pregnancy

Abstract Ittrich’s method for the determination of total estrogens in urine (1) was adapted for automation on the AutoAnalyzer, using a continuous digester module for the combined operation of phase exchange and color development. The automated method gave good recovery and reproducibility, and correlated well with the manual method. It increased the capacity of this laboratory for estrogen determinations, improved the turnover rate, and reduced the labor involved to a minimum.

Automated Determination of Phosphorus in Fertilizers Collaborative Study

1978 ◽  
Vol 61 (3) ◽  
pp. 533-536
Author(s):  
Frank J Johnson
Keyword(s):  
Collaborative Study ◽  
Available Phosphorus ◽  
Matched Pairs ◽  
Automated Method ◽  
Complete Sets ◽  
Automated Determination

Abstract An automated method for determining total and direct available P2O5 in fertilizers was compared to the official final action gravimetric quinolinium molybdophosphate and spectrophotometric molybdovanadate methods in a collaborative study. Ten samples were sent to 10 collaborators for analysis. Eight complete sets of data were returned, and the ninth collaborator returned data for direct available phosphorus by the automated method only. The data were statistically analyzed by the technique of closely matched pairs. No significant overall difference was found between methods or among collaborators. The automated method has been adopted as official first action for phosphorus.

Automated Fluorometric Method for the Determination of Total Vitamin C in Food Products

1976 ◽  
Vol 59 (6) ◽  
pp. 1244-1250 ◽  
Author(s):  
Ram B Roy ◽  
Aldo Conetta ◽  
Jerry Salpeter
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Food Products ◽  
Total Vitamin ◽  
Automated Method ◽  
Highly Sensitive ◽  
Aoac Method ◽  
Analytical System

Abstract A specific microfluorometric method for the determination of ascorbic acid, dehydroascorbic acid, and total vitamin C in food products has been automated. The procedure developed is an adaptation of the official AOAC method (secs. 43.056–43.062), except that N-bromosuccinimide is used instead of Norit to oxidize vitamin C. Ascorbic acid is selectively oxidized by N-bromosuccinimide before other interfering substances that may be present, so this method is a highly sensitive and specific technique with extensive applicability. The proposed automated method is simple, rapid, reliable, and sufficiently sensitive to analyze as little as 2 × 10−3 to 0.1 mg ascorbic acid/ml. Analytical results obtained for ascorbic acid, dehydroascorbic acid, and total vitamin C in a wide variety of food products are reported. The analytical system developed has the capability of analyzing 50 samples/hr.

scholarly journals Application of Sparging to the Automated Ion Selective Electrode Determination of Kjeldahl Nitrogen

1980 ◽  
Vol 63 (4) ◽  
pp. 931-936
Author(s):  
Ram B Roy ◽  
John Jansen ◽  
Michael Sahn
Keyword(s):  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Ammonia Sensing ◽  
Automated Method ◽  
Significant Difference ◽  
Naoh Solution ◽  
Kjeldahl Digestion ◽  
Aoac Method ◽  
Kjeldahl Nitrogen

Abstract An automated method has been developed for the determination of total Kjeldahl nitrogen. Sample digests are mixed with a NaOH solution and allowed to make contact with air flowing at 1000 mL/min. The mixture enters the inlet of a heating bath maintained at 75°C. On exit, ammonia gas separates from a sparging vessel and is trapped as ammonium sulfate in a dilute H2SO4 solution. An aliquot of the acid solution is resampled and made alkaline to generate ammonia, which is measured by an ammonia sensing probe. A comparison of this procedure with AOAC method 7.025 shows that the procedure is accurate and that there is no statistically significant difference between them. This procedure introduces a new approach to eliminate the interfering species present in sample digests after Kjeldahl digestion for automated ion selective electrode measurements of ammonia. Thirty samples/h can be analyzed by this method.

Method for Fully Automated Determination of Total Cholesterol in Blood Serum, Including Saponification and Extraction

1968 ◽  
Vol 14 (10) ◽  
pp. 960-966 ◽  
Author(s):  
J van der Honing ◽  
C C Saarloos ◽  
J Stip
Keyword(s):  
Carbon Tetrachloride ◽  
Blood Serum ◽  
Total Cholesterol ◽  
Standard Error ◽  
New Method ◽  
Automated Method ◽  
The Relationship ◽  
Cholesterol Determination ◽  
Automated Determination

Abstract A fully automated method has been developed for the determination of total cholesterol in blood serum, using the AutoAnalyzer system. According to the new method, based on the cholesterol determination of Abell et al. (1), the serum sample is saponified and subsequently extracted with carbon tetrachloride. After treatment with Liebermann-Burchard reagent, the amount of cholesterol is determined at 630 nm. The method can be used for free and esterified cholesterol because saponification is carried out. The relationship between the new method and that of Abell et al. is linear. The correlation coefficient is 0.98 and the standard error 1.5%. According to the new method, 30 samples can be analyzed per hour.

Comparison of Semiautomated and Manual Methods for the Determination of Thiamine in Baby Cereals and Infant and Dietary Formulas

1977 ◽  
Vol 60 (3) ◽  
pp. 737-738
Author(s):  
Wallace M Ribbron ◽  
Kenneth E Stevenson ◽  
James R Kirk
Keyword(s):  
Manual Method ◽  
Standard Curve ◽  
Thiamine Content ◽  
Manual Methods ◽  
The Mean ◽  
Semiautomated Method

Abstract Using a semiautomated method, the mean thiamine content of specific products ranged from 88 to 101% and 83 to 93% for baby cereals and infant and dietary formulas, respectively, of those obtained with the AOAC manual method. The best results were obtained when data for the semiautomated method were calculated from a standard curve obtained by using thiamine solutions which had been digested and hydrolyzed along with the samples.

Automated Determination of Fluvoxamine in Plasma by Column-Switching High-Performance Liquid Chromatography

1992 ◽  
Vol 38 (10) ◽  
pp. 2082-2086 ◽  
Author(s):  
S Härtter ◽  
H Wetzel ◽  
C Hiemke
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Column Switching ◽  
Reversed Phase ◽  
Therapeutic Monitoring ◽  
Detector Response ◽  
Serum Samples ◽  
Automated Method ◽  
Automated Determination

Abstract A column-switching system with high-performance liquid-chromatographic separation and ultraviolet detection is described for automated determination of fluvoxamine in human plasma or serum. Samples were injected and the drug was retained in a clean-up column [20 x 4.6 mm (i.d.)] filled with C8 reversed-phase material (10-micron particles). After unwanted material was washed out, the drug was eluted and separated with an analytical chromatography column, 4.6 x 250 mm (i.d.), filled with Nucleosil 100 CN (5-micron particles) with an acetonitrile:methanol:0.01 mol/L phosphate buffer eluent (188:578:235 by vol) at a flow rate of 1.5 mL/min for < 20 min and detected by spectrometry at 214 nm. With oxaprotiline as internal standard, fluvoxamine could be easily quantified, and it was well separated from endogenous plasma constituents and various psychoactive drugs. The detection limit was 10 micrograms/L (31.6 nmol/L), the analytical recoveries were 97-100%, and the relationship between drug concentration and detector response was linear from 0 to 1000 micrograms/L (3160 nmol/L). The automated method is suitable for therapeutic monitoring of fluvoxamine in the treatment of psychiatric patients.

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