Automated multiple flow-injection analysis in clinical chemistry: determination of albumin with bromcresol green.

1980 ◽  
Vol 26 (2) ◽  
pp. 331-334 ◽  
Author(s):  
B W Renoe ◽  
K K Stewart ◽  
G R Beecher ◽  
M R Wills ◽  
J Savory

Abstract We describe an adaptation of automated multiple flow-injection analysis instrumentation to an analysis for albumin in serum. The bromcresol green reaction was used to test the utility of the system. The approach yielded albumin results with excellent sensitivity, no measurable carryover, a relative standard deviation of less than 1%, good correlations with published procedures, and no measurable interferences. The simplicity and flexibility of the instrumentation and its performance integrity, as indicated by the analytical results, make this a viable clinical chemical tool.

1980 ◽  
Vol 26 (2) ◽  
pp. 331-334
Author(s):  
B W Renoe ◽  
K K Stewart ◽  
G R Beecher ◽  
M R Wills ◽  
J Savory

Abstract We describe an adaptation of automated multiple flow-injection analysis instrumentation to an analysis for albumin in serum. The bromcresol green reaction was used to test the utility of the system. The approach yielded albumin results with excellent sensitivity, no measurable carryover, a relative standard deviation of less than 1%, good correlations with published procedures, and no measurable interferences. The simplicity and flexibility of the instrumentation and its performance integrity, as indicated by the analytical results, make this a viable clinical chemical tool.


1991 ◽  
Vol 13 (4) ◽  
pp. 143-146 ◽  
Author(s):  
Celio Pasquini ◽  
Lourival C. de Faria

A flow injection analyser has been constructed to allow an operator-free determination of up to 40 samples. Besides the usual FIA apparatus, the analyser includes a home-made sample introduction device made with three electromechanical three-way valves and an auto-sampler from Technicon which has been adapted to be commanded by an external digital signal. The analyser is controlled by a single board SDK-8085 microcomputer. The necessary interface to couple the analyser components to the microcomputer is also described. The analyser was evaluated for a Cr(VI)-FIA determination showing a very good performance with a relative standard deviation for 15 signals from the injection of 100 μl of a 1.0 mg.ml-1standard Cr(VI) solution being equal to 0.5%.


2010 ◽  
Vol 113-116 ◽  
pp. 1732-1734
Author(s):  
Xin Zhao ◽  
Zhi Hui Sui ◽  
Jing Bin Zhang

In 1.0 mol/L H2SO4 solution, a rapid and simple flow—injection spectrophotometric method has been developed for Cr(Ⅵ) determination, based on the violet—red Cr(Ⅵ)—diphenylcarbazide chelates formed by reactions. The results show, under optimum conditions, the maximum absorption of the complex is at 540 nm and the detection limits of the method is 0.0136mg/L for Cr(Ⅵ) and Beer’s law is obeyed for Cr(Ⅵ) in the range of 0.03—1.60mg/L. The determination frequency is l00 times/h. The relative standard deviation of eleven replicates is less than 4.0%. The method has been applied to the determination of trace Cr(Ⅵ) in tanning wastewater with satisfactory results.


2005 ◽  
Vol 88 (4) ◽  
pp. 1064-1068 ◽  
Author(s):  
Suzana L Castro ◽  
Osmundo D Pessoa Neto ◽  
Sergio R B Santos ◽  
Everaldo P Medeiros ◽  
Ricardo A C Lima ◽  
...  

Abstract A flow-injection biamperometric method for determination of pantoprazole (PTZ) in pharmaceutical tablets is reported for the first time. The reversible redox couples Fe3+/Fe2+, Fe(CN)63−/Fe(CN)64−, Ce4+/Ce3+, VO3−/VO2+, and I2/I− were tested as indicating redox systems for biamperometric determination of PTZ in a flow-injection assembly with optimized flow parameters. The best results were obtained using VO3−/VO2+, which showed to be a selective and sensitive biamperometric indicating system for PTZ even in the presence of excipients and antioxidants that typically are found in drugs. The analytical graph was linear (r = 0.99945) in the range from 10 to 100 mg/L using 25 mmol/L VO3− as the reagent and water as the carrier stream and applying 100 mV between the 2 platinum wire electrodes. The limits of detection and quantitation were 200 and 667 μg/L, respectively, with a sensibility of calibration of 22.6 mV/mg/L. The proposed method was successfully applied to determine PTZ in commercial pharmaceutical tablets with a mean relative error of 1.60% (n = 5) and mean relative standard deviation of 3.10%. Recoveries close to 100% showed good agreement between the expected amount of PTZ in tablets (40 mg) and the results found by the application of the proposed method and demonstrated that the formulations used in the tablet compositions do not interfere in the PTZ analysis. The system had good stability, with a relative standard deviation of 3.80% for 9 sequential injections of a 60 mg/L PTZ solution. A sampling rate of about 100 samples/h was obtained.


Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate


1998 ◽  
Vol 81 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming

Abstract The classic method for determination of milk casein is based on precipitation of casein at pH 4.6. Precipitated milk casein is removed by filtration and the nitrogen content of either the precipitate (direct casein method) or filtrate (noncasein nitrogen; NCN) is determined by Kjeldahl analysis. For the indirect casein method, milk total nitrogen (TN; Method 991.20) is also determined and casein is calculated as TN minus NCN. Ten laboratories tested 9 pairs of blind duplicate raw milk materials with a casein range of 2.42- 3.05℅ by both the direct and indirect casein methods. Statistical performance expressed in protein equivalents (nitrogen ⨯ 6.38) with invalid and outlier data removed was as follows: NCN method (wt%), mean = 0.762, sr = 0.010, SR = 0.016, repeatability relative standard deviation (RSDr) = 1.287℅, reproducibility relative standard deviation (RSDR) = 2.146%; indirect casein method (wt℅), mean = 2.585, repeatability = 0.015, reproducibility = 0.022, RSDr = 0.560℅, RSDR = 0.841; direct casein method (wt℅), mean = 2.575, sr = 0.015, sR = 0.025, RSDr = 0.597℅, RSDR = 0.988℅. Method performance was acceptable and comparable to similar Kjeldahl methods for determining nitrogen content of milk (Methods 991.20, 991.21,991.22, 991.23). The direct casein, indirect casein, and noncasein nitrogen methods have been adopted by AOAC INTERNATIONAL.


2013 ◽  
Vol 448-453 ◽  
pp. 406-408
Author(s):  
Jing Liu ◽  
Xiao Na Ji ◽  
Qing Kai Ren ◽  
Sheng Shu Ai ◽  
Li Jun Wan ◽  
...  

We established a method fordetermination of nitrate in water by High Performance Liquid Chromatography(HPLC). The sample was analysed by HPLC-ADA and was quantitated by externalstandard method after being simply processed. This methd has the advantages ofhigh separation efficiency and fast analysis. The experiment result showed thatthe linearly dependent coefficient was0.994, the recovery rate was between 98.7%~105.7%,the relative standard deviation(RSD)wasless than 2.1 %, and the lowest detectable limit is 0.01ng (S/N=1.6).


2005 ◽  
Vol 88 (5) ◽  
pp. 1404-1412 ◽  
Author(s):  
Sarah Hasnip ◽  
Colin Crews ◽  
Nicholas Potter ◽  
Paul Brereton ◽  
Henri Diserens ◽  
...  

Abstract An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96–130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9–23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9–35.3%, and HorRat values of between 1.0 and 1.6 were obtained.


2018 ◽  
Vol 33 (2) ◽  
pp. 47
Author(s):  
Orlando Fatibello-Filho ◽  
Heberth Juliano Vieira

A spectrophotometric flow injection method for the determination of paracetamol in pharmaceutical formulations is proposed. The procedure was based on the oxidation of paracetamol by sodium hypochloride and the determination of the excess of this oxidant using o-tolidine dichloride as chromogenic reagent at 430 nm. The analytical curve was linear in the paracetamol concentration range from 8.50 x 10-6 to 2.51 x 10-4 mol L-1 with a detection limit of 5.0 x 10-6 mol L-1. The relative standard deviation was smaller than 1.2% for 1.20 x 10-4 mol L-1 paracetamol solution (n = 10). The results obtained for paracetamol in pharmaceutical formulations using the proposed flow injection method and those obtained using a USP Pharmacopoeia method are in agreement at the 95% confidence level.


2008 ◽  
Vol 27 (2) ◽  
pp. 149 ◽  
Author(s):  
Ivana Savić ◽  
Goran Nikolić ◽  
Vladimir Banković

Simple, accurate and reproducible UV-spectrophotometric method was developed and validated for the estimation of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. Phenylephrine hydrochloride was estimated at 291 nm in 1 mol⋅dm-3 sodium hydroxide (pH 13.5). Beer’s law was obeyed in the concentration range of 10–100 μg⋅cm−3 (r2 = 0.9990) in the sodium hydroxide medium. The apparent molar absorptivity was found to be 1.63×103 dm3⋅mol−1⋅cm−1. The method was tested and validated for various parameters according to the ICH (International Conference on Harmonization) guidelines. The detection and quantitation limits were found to be 0.892 and 2.969 μg⋅cm−3, respectively. The proposed method was successfully applied for the determination of phenylephrine hydrochloride in pharmaceutical nasal drops formulations. The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 1 %), while being simple, cheap and less time consuming, and hence can be suitably applied for the estimation of phenylephrine hydrochloride in different dosage forms.


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