scholarly journals Direct determination of calcium in milk by atomic absorption spectrometry using flow-injection analysis

2007 ◽  
Vol 32 (3) ◽  
pp. 25-30 ◽  
Author(s):  
M. B. Petrovich ◽  
V. R. A. Filho ◽  
J. A. G. Neto
Keyword(s):  
Reference Materials ◽  
Flow Injection ◽  
Direct Determination ◽  
Absorption Spectrometry ◽  
Sample Volume ◽  
Standard Reference Materials ◽  
Injection System ◽  
Relative Standard ◽  
Flow Injection System ◽  
Assisted Decomposition

A flow-injection system with sample and reagent addition by the synchronous merging zones approach for calcium determination in milk by flame AAS is proposed. Main parameters were optimized using a factorial design with central point. The optimum conditions were 2.5% (m/v) for La concentration, 8 mL min-1 for the carrier flow-rate, 20 cm for coiled reactor and 250 ìL for sample volume. Different sample preparation procedures were evaluated such as dilution in water or acid and microwave-assisted decomposition using concentrated or diluted acids. The optimized flow system was applied to determine Ca in eleven commercial milk samples and two standard reference materials diluted in water. Similar calcium levels were encountered comparing the results obtained by the proposed method (dilution in water) with those obtained using microwave-oven digestion. Results obtained in two standard reference materials were in agreement at 95% confidence level with those certified. Recoveries of spiked samples were in the 93% - 116% range. Relative standard deviation (n = 12) was < 5.4% and the sample throughput was 150 measurements per hour, corresponding to a consumption of 250 µL of sample and 6.25 mg La per determination.

scholarly journals Flow injection analysis of nitrogen dioxide using a galvanic detector

1998 ◽  
Vol 20 (1) ◽  
pp. 17-21
Author(s):  
Shan-jun Liu ◽  
Han-xi Shen ◽  
Jian-xing Feng ◽  
M. Tubino
Keyword(s):  
Nitrogen Dioxide ◽  
Flow Injection ◽  
Sample Volume ◽  
Injection System ◽  
Flow Monitoring ◽  
Relative Standard ◽  
Flow Injection System ◽  
Gaseous Sample ◽  
Monitoring Application

A flow injection configuration (FIA) based on a galvanic detector for the determination of nitrogen dioxide is described. The gaseous sample is directly injected into a gaseous carrier. The sample is transported toward the detector. The steady state measurements are not required to obtain the reproducible peak signals. The features of FIA are compared with that of continuous flow monitoring application. The flow injection system is simple, rapid and capable of detecting NO2in the range of 1-500 ppm (v/v). The measuring range and sensitivity of the galvanic detector in FIA depend on the sample volume. A relative standard deviation is 2.4%(n=10)for 200 ppm (v/v) of nitrogen dioxide. The sampling frequency is about 24 h-1

scholarly journals Determination of Picogram Levels of Roxithromycin in Pharmaceutical, Human Serum, and Urine by Flow-Injection Chemiluminescence

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Jiangman Liu ◽  
Huan Yang ◽  
Yun Zhang ◽  
Min Wu ◽  
Haixiang Zhao ◽  
...  
Keyword(s):  
Human Serum ◽  
Flow Injection ◽  
Limit Of Detection ◽  
Inhibitory Effect ◽  
Injection System ◽  
Relative Standard ◽  
Flow Injection System ◽  
Flow Injection Chemiluminescence ◽  
Serum And Urine

A sensitive chemiluminescence (CL) method, based on the inhibitory effect of roxithromycin (ROX) on the CL reaction between luminol and dissolved oxygen in a flow-injection system, was first proposed for the determination of ROX at picogram levels. The decrement of CL intensity was linearly proportional to the logarithm of ROX concentrations ranging from 0.1 to 100 pg mL-1, giving the limit of detection (LOD) of 0.03 pg mL-1 (3σ). At a flow rate of 2.0 mL min-1, a complete analytical procedure including sampling and washing could be performed within 0.5 min, with relative standard deviations (RSDs) of less than 5.0% (n=5). The proposed procedure was applied successfully to the determination of ROX in pharmaceutical, human serum, and urine with the recoveries ranging from 90.0 to 110.0%.

A simple turbidimetric flow injection system for saccharin determination in sweetener products

2010 ◽  
Vol 64 (3) ◽  
Author(s):  
Camila Mendes ◽  
Emiliane Laignier ◽  
Maisa Brigagão ◽  
Pedro Luccas ◽  
César Tarley
Keyword(s):  
Flow Injection ◽  
Hplc Method ◽  
Chloride Ions ◽  
Injection System ◽  
Precipitation Reaction ◽  
Relative Standard ◽  
Flow Injection Analysis System ◽  
Flow Injection System ◽  
Analysis System ◽  
Sodium Cyclamate

AbstractA new method for saccharin determination in liquid sweetener products was developed. The method is based on the precipitation reaction of Ag(I) ions with saccharin in aqueous medium (pH 3.0), using a flow injection analysis system with merging zones, the suspension was stabilized with 5 g L−1 Triton X-100. All experimental parameters influencing the flow injection system were optimized by means of chemometric approaches. The linear analytical curve was built from 2.4 g L−1 up to 9.64 g L−1 (r = 0.9968) with a quantification limit of 2.40 g L−1. The precision assessed as relative standard deviation (n = 10) was found to be 1.75 % for the saccharin concentration of 7.20 g L−1. Based on interference studies performed with the substances commonly found in liquid sweeteners, such as sodium cyclamate, methylparaben, sodium aspartame, and benzoic and citric acids, at the analyte to interferent mole ratio of up to 1: 10, no interference with the saccharin determination was observed. The presence of chloride ions interferes with the method, but a preceding liquid-liquid saccharin extraction with ethyl acetate was successfully employed to overcome this drawback. Accuracy of the method in sweetener products was evaluated by a comparison with the HPLC method.

scholarly journals Continuous online determination of 226Ra in liquid effluents using automated column chromatography-ICP-MS

2015 ◽  
Vol 93 (11) ◽  
pp. 1226-1231 ◽  
Author(s):  
R. Douglas Evans ◽  
Andrei Izmer ◽  
Karima Benkhedda ◽  
Andrew Toms ◽  
Angelo Fernando ◽  
...  
Keyword(s):  
Flow Injection ◽  
Limit Of Detection ◽  
Sample Volume ◽  
Injection System ◽  
Automatic Integration ◽  
Icp Ms ◽  
On Line ◽  
Flow Injection System ◽  
Matrix Removal ◽  
Control Column

A measurement system capable of continuous on-line matrix removal, pre-concentration and analysis of 226Ra using pre-packed columns coupled to a flow injection system and an ICP-MS was developed. Full instrumental control of both the ICP-MS and the flow injection system provided automatic integration of the transient signals. The flow injection system was programmed to control column conditioning, sample loading, column rinsing, analyte elution and column cleaning operations employing appropriate solutions. The application of this system to the 226Ra analysis of an industrial liquid effluent was demonstrated. Using this particular instrument together with pre-concentration and matrix removal procedures, a limit of detection of 5.4 fg L−1 (2 mBq L−1) and a method detection limit of 16.2 fg L−1 (6 mBq L−1) were achieved for the measurement of 226Ra using a 25 mL sample volume. Total time for sample handling and analysis is approximately 10 minutes. The concentration of 226Ra in a discharged effluent sample was 0.73 pg L−1 (27 mBq L−1), which is in good agreement with the value of 0.81 pg L−1 (30 mBq L−1) measured using conventional alpha counting techniques.

Direct determination of therapeutic concentrations of lithium in serum by flow-injection analysis with atomic absorption spectroscopic detection.

1982 ◽  
Vol 28 (3) ◽  
pp. 440-443 ◽  
Author(s):  
B F Rocks ◽  
R A Sherwood ◽  
C Riley
Keyword(s):  
Atomic Absorption ◽  
Flow Injection ◽  
Direct Determination ◽  
Injection System ◽  
Analytical Recovery ◽  
Flow Injection System ◽  
Dilution Effects ◽  
Sodium And Potassium ◽  
Sample Dilution

Abstract In this flow-injection system for direct determination of lithium in serum by atomic absorption spectroscopy, the 10-microL sample is manually injected into a continuously flowing non-segmented stream of de-ionized water, which is pumped, via a dispersion tube, to the spectrometer's nebulizer. Controlled dispersion of the sample zone, before it is introduced into the nebulizer, produces the required sample dilution. Effects of varying the length of the dispersion tube, the flow rate, and the sample size were studied. Analytical readout is obtained, in the form of transient peaks, 5 s after sample injection. It is necessary to include physiological concentrations of sodium and potassium in the standard because each of these cations enhances the lithium absorbance signal. Analytical recovery (98.5 to 101%) and CV (about 2%) are good, and results compare well with those obtained by aspiration of prediluted samples (n = 121, r = 0.99).

Sign in / Sign up

Export Citation Format

Share Document