Sequential injection analysis coupled to on-line benchtop proton NMR: Method development and application to the determination of synthetic cathinones in seized drug samples

Talanta ◽  
2021 ◽  
Vol 231 ◽  
pp. 122355
Author(s):  
Timothy J. Trinklein ◽  
Malati Thapa ◽  
Lexie A. Lanphere ◽  
John A. Frost ◽  
Sandra M. Koresch ◽  
...  
Keyword(s):  
Method Development ◽  
Proton Nmr ◽  
Synthetic Cathinones ◽  
Sequential Injection Analysis ◽  
Sequential Injection ◽  
Nmr Method ◽  
On Line

scholarly journals A Simple Automated Method for the Determination of Nitrate and Nitrite in Infant Formula and Milk Powder Using Sequential Injection Analysis

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Mariela Pistón ◽  
Alicia Mollo ◽  
Moisés Knochen
Keyword(s):  
Milk Powder ◽  
Sequential Injection Analysis ◽  
Sequential Injection ◽  
Liquid Form ◽  
Automated Method ◽  
Nitrate Determination ◽  
On Line ◽  
Nitrate And Nitrite ◽  
User Friendly

A fast and efficient automated method using a sequential injection analysis (SIA) system, based on the Griess, reaction was developed for the determination of nitrate and nitrite in infant formulas and milk powder. The system enables to mix a measured amount of sample (previously constituted in the liquid form and deproteinized) with the chromogenic reagent to produce a colored substance whose absorbance was recorded. For nitrate determination, an on-line prereduction step was added by passing the sample through a Cd minicolumn. The system was controlled from a PC by means of a user-friendly program. Figures of merit include linearity (r2> 0.999 for both analytes), limits of detection (0.32 mg kg-1NO3-N, and 0.05 mg kg-1NO2-N), and precision (sr%) 0.8–3.0. Results were statistically in good agreement with those obtained with the reference ISO-IDF method. The sampling frequency was 30 hour-1(nitrate) and 80 hour-1(nitrite) when performed separately.

scholarly journals Using Sequential Injection Analysis to Improve System and Data Reliability of Online Methods: Determination of Ammonium and Phosphate in Coastal Waters

2007 ◽  
Vol 2007 ◽  
pp. 1-6 ◽  
Author(s):  
Carsten Frank ◽  
Friedhelm Schroeder
Keyword(s):  
Coastal Waters ◽  
Method Development ◽  
Flow System ◽  
Sequential Injection Analysis ◽  
Sequential Injection ◽  
Method Development And Validation ◽  
Standard Additions ◽  
Online Methods ◽  
Development And Validation

This article summarises the advantages of the sequential injection analysis (SIA) for the online determination of nutrients in coastal waters. It concentrates on techniques to improve the reliability of the gained data by continuously monitoring one or more standards and on the advantages of online standard additions and offline determination of manually collected samples with the online SIA system. These measures are advantageous during method development and validation and can be used to verify the system performance on a regular base to reduce the amount of erroneous results. No changes in the flow system are necessary and the sample throughput is only slightly reduced. These techniques have been applied to a SIA system which is able to simultaneously determine ammonium and phosphate at a rate of more than 100 samples per hour each and detection limits (3σ) of 0.06μM and 0.05μM. Results from a campaign in summer 2005 are shown.

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