Quantitative Determination of Fluoroquinolones in Contaminated Soils by HPLC with Solid-Phase Extraction

This work reports the development of an analytical method for the simultaneous analysis of three fluoroquinolones; ciprofloxacin (CIP), norfloxacin (NOR) and ofloxacin (OFL) in soil matrix. The proposed method was performed by using microwave-assisted extraction (MAE), solid-phase extraction (SPE) for samples purification, and finally the pre-concentrated samples were analyzed by HPLC detector. In this study, various organic solvents were tested to extract the test compounds, and the extraction performance was evaluated by testing various parameters including extraction solvent, solvent volume, extraction time, temperature and number of the extraction cycles. The current method showed a good linearity over the concentration ranging from 1 – 300ng g-1 with correlation coefficients (r2 > 0.998) for all test compounds. Good recoveries were also obtained for the test compounds ranged from 89 – 99 %. The relative standard deviation (RSD) from intra-day and inter-day precision was lower than 7%, and the detection (LOD) and quantification (LOQ) limits ranged from 0.9 – 2.7ng g-1.Finally, the proposed method was applied to determine the target compounds in real soil samples irrigated with wastewater. The results confirm the presence of the test compounds in soils with values ranging from 1.9 – 4.6ng g-1, as well as the suitability of the proposed method to determine the test compounds in real soil matrix as well as the ability of the test compounds to accumulate in soils irrigated with sewage.

Double entry method for the verification of data a chromatography data system receives

The importance of software validation increases since the need for high usability and suitability of software applications grows. In order to reduce costs and manage risk factors, more and more recommendations and rules have been established. In the field of pharmacy the vendors of so-called chromatography data systems (CDSs) had to implement the guidelines of the Code of Federal Regulations Title 21 (CFR 21) during the last few years in order to fulfill the increasing requirements. The CFR 21 part 11 deals with electronic records and signatures. This part is binding for each company in the regulated environment that wishes to create, edit and sign electronic information instead of printing them on paper. Subsection CFR 21 part 11.10(h) explains how to perform an input check for manual user entries as well as for data that will be collected from an external device. In this article we present an approach performing the double entry method on data provided by the hardware instrument in order to investigate possible influences on the raw data by the handling CDS. A software tool has been written which allows us to communicate with a high-performance liquid chromatography (HPLC) detector and acquire data from it. The communication is completely independent of a CDS which is started separately and connected to the same system. Using this configuration we made a parallel data acquisition of two instances at the same time possible. Two CDSs have been tested and for at least one of them it has been shown that a comparison of the acquired data can be done as with the double entry method for the data verification. For the second CDS we checked whether it would be applicable after a few modifications. The given approach could be either used for a live data verification of produced raw data or as a single test during a software operational qualification to verify the data acquisition functionality of the software.

Proving the Preclusion of Data Manipulation Using Parallel Data Acquisition in Chromatography

Traceability has an enormous value for companies, but especially for those working in the regulated environment. It plays a special role in the field of pharmacy with respect to manufacturing, controlling and distributing batches of drugs. Through the guidance of Good Manufacturing Practice (GMP) traceability should be ensured. An increasing number of pharmaceutical companies are member of one of the global pharmacopoeias (United States Pharmacopeia, European Pharmacopeia and Japanese Pharmacopeia). The specifications of these pharmacopoeias describe the best practice in documentation, control, qualification and risk management. But however, the pharmacopoeias are written very generally and do not distinguish between the vendors of the analytical instruments. Here, we analyze how chromatographic analyses and data acquisition rely on a specific vendor of the device and the chromatography data system (CDS), the controlling software. We present a way to compare the data acquisition of different CDSs communicating with HPLC instruments. A newly developed software called Data Collector allows the acquisition of data from a HPLC detector parallel to the controlling CDS in the same run. Two HPLC systems and two different CDSs using a well defined sample standard have been tested. The direct comparison of the acquired data precludes unexpected data manipulations of both tested CDSs and shows that there are primarily deviations between the CDSs due to time variations only which depend on the sampling rate. All in all the Data Collector can be used for the traceability of data acquisition.

Analysis of Rhodamine B in Chinese Wolfberry from Market Sale by HPLC

Based on the method of high performance liquid chromatography - diode array detector (HPLC - DAD) ,this experiment rapidly detected rhodamine B of Chinese wolfberry from market sale. Rhodamine B in the samples was dissolved by hexane.And after it was evaporated, it was extracted quantitatively.And then rhodamine B was measured with high performance liquid chromatography (HPLC) detector, using external standard method of peak area for quantitation. Results showed that the test conditions: 80 percent methanol and 20 percent water as mobile phase; sample volume was 20 μL ; column temperature was 35 degree centigrade; the flow rate was 1.0 ml per min and detection wavelength of 545nm, a reference to the wavelength of 600nm.Rhodamine B of the linear correlation coefficient was 0.9998 between the concentration of 0.06 and 0.20μg per ml. The stability of the method was in the range of 2.4 percent to 3.3 percent, precision was about 1.60 percent, recovery rate determination results were between 85.75 percent and 103.80 percent,The positive rate of rhodamine B was 80 percent. This method has the advantages of simple, rapid and accurate, and is very suitable for the determination of rhodamine B in Chinese wolfberry.

A simple microfluidic electrochemical HPLC detector for quantifying Fenton reactivity from welding fumes

Development and characterization of a simple microfluidic electrochemical flow cell that can be coupled with HPLC to enable dual absorbance/electrochemical detection is described.