QuEChERS – More Advanced Pesticide Analysis

The QuEChERS method was originally designed to extract pesticides from fruits and vegetables. The combination of salting out and d-SPEpurification in the initial liquid-liquid extraction also showed satisfactory results in the multi-residue analysis of pesticides, veterinary drugs, and mycotoxins in various foods and agricultural products. Hawach QuEChERS solution offers many advantages over other pesticide analysis products and technologies:

1. Easy and straightforward, almost no training is required
2. Reduced overall sample preparation time
3. Products from the same supplier, better consistency and reliability
4. Efficient, economical, suitable for analysis of multiple commodities
5. Better consistency of extracted targets
6. Improve laboratory efficiency and improve laboratory workflow
7. Improve the stability of the results

How to Use Stainless Steel Vacuum Filtrations

The laboratory vacuum filter unit is designed for laboratory users to filter solid-liquid separation of liquid samples.

Stainless Steel Vacuum Filtrations operation steps:

1. Place the glass filter bottle on the stainless steel vacuum filtrations and insert the silicone plug of the funnel base into the filter bottle.
2. Use a line to connect the filter pump port and the filter bottle.
3. Lay the filter in the funnel base and gently rotate it with the filter bowl.
4. Connect the yellow bottom drain tube to the bottom drain port of the suction filter bottle. The drain tube is clamped with the clamp.
5. Press the power switch again to start the filter pump.
6. Pressure regulators can be used to adjust vacuum (suction) and filtration rate.

The body material of the all-stainless steel surface can be cleaned by simply wiping with a cloth during routine maintenance.

In addition, customers should pay attention to the following matters, good use habits can avoid human damage and extend the life of the machine. Considerations include:

1. Check that the voltage marked on the nameplate on the back of the instrument matches the local voltage.
2. Use the instrument in a clean, dust-free, ventilated space with a temperature below 40 °C.
3. The front of the vacuum filter unit has a buffer cup to prevent a large amount of aqueous solution from being drawn into the filter pump, but it is not completely prevented. Please take care to prevent the liquid from sucking back. If you have already taken in the liquid, stop using it immediately and send it for repair as soon as possible.
5. The stainless steel vacuum filtrations must be placed on a level desktop.
6. Turn off the power before installing or removing the silicone tube.
7. Do not move, collide or tilt the machine while the instrument is in operation.
8. The filter element is used to prevent dust from entering the filter pump and to purify the gas at the gas outlet, so that impurities will not be sucked into the pump. Please check regularly, if the color changes significantly, please contact the dealer for replacement.

Hawach Scientific Glass Solvent Filter

Introduction of Hawach scientific glass solvent filters

Hawach scientific glass solvent filters with high-quality glass material, uniform wall thickness, no bubbles, beautiful appearance, can be used for sterilization under high temperature and pressure, good sealing performance, fast flow, standard grinding mouth. The device is lined with a microporous membrane, which can be used for chemical analysis, health inspection, biological pharmaceutical and pesticide, petroleum, environmental protection testing and other aspects of sample filtration. To detect and remove particles and bacteria from the liquid. More detail information from info@hawach.com
Structure

This device is made of high-quality glass, It is divided into three parts: upper, middle and lower parts. The upper part is a cup type grinding port container named filter cup. The capacity is divided into 300ml and 500ml, in the middle is an internal grinding mouth support device with a suction nozzle.

There is a flat glass sand chip in the center for supporting the filter membrane, called the filter head, corresponding specifications are 1L and 2L. The lower end is a pressure vessel with an external grinding mouth, which is called a triangular bottle; The corresponding capacities are 1000ml and 2000ml and equipped with aluminum alloy special clamps for the whole device with a tight connection, clamps through an oxidation treatment, chemical corrosion resistance.

Product Code: SLGSF03001
300ml Glass Solvent Filters
– 300ml glass funnel.
– 1000ml glass collection bottle.
– Anodized aluminum spring clamp.
– Support frit and base. The whole set can be autoclaved at 121° C

Product Code : SLGSF05002
500ml Glass Solvent Filters
– 500ml glass funnel.
– 2000ml glass collection bottle.
– Anodized aluminum spring clamp.
– Support frit and base. The whole set can be autoclaved at 121° C

Anion HPLC Columns Characteristics and Operational Considerations

Anion HPLC columns characteristics

(1)The Anion HPLC columns are high capacity, high efficiency, hydrophobic anion exchange column. Used to separate a wide range of valence anions, including polyphosphates, polyphosphates, and other multivalent complex reagents such as EDTA and NTA.
(2)Use polyphosphates, and chelating agents in complex sample matrices.
(3)Sulfide was determined using sodium hydroxide and wastewater samples for amperometric detection.
(4)Analysis of the use of hexavalent chromium columns after the reaction and environmental media absorption of visible light detection, including wastewater chromium, drinking water, and air.
(5)Separate inorganic and organic species of arsenic and urine samples in drinking water.
(6)High capacity, higher resolution.
(7)Longer retention times are required, but the resolution is higher.
(8)Promote rapid analysis of organic acids and anions in well-characterized samples.
(9)Particularly suitable for separating complex sample matrices or uncharacterized organic acids and anions in samples.
(10)Recommended for monovalent and divalent organic acids.

Anion HPLC columns operation precautions

(1) The column must be connected to the chromatograph after the column’s flow line is completely filled with the eluent.
(2) Connect the column to the direction of the flow path identified on the column.
(3) An appropriate amount of organic solvent may be added to the eluent for modification (less than 50% acetonitrile or methanol, etc.).
(4) The recommended temperature is 35C. It is recommended to use a column oven. The temperature has a certain correlation with the elution time of each ion. When the temperature changes, the elution time of the ions changes.
(5) After the pump is turned on, keep the flow rate below 0.5mLUmin, and then gradually increase the flow rate to the working flow.
(6) For samples containing organic matter and impurities, please pre-process the sample before injecting the sample.

Choose Your Suitable SPE Cartridges

As we all know, the principle of the SPE method is the rule of similarity. So it is of great importance to choose the right paddings’ SPE Cartridges.

Based on separation modes, we can divide them into 3 groups:

1. Normal Phase C18, C18-Ne, C8, C2, PHE, CN

Utilizes the difference between the adsorption among the solid adsorbent paddings and the target compound in the sample and the adsorption of the sample matrix and the interfering compound, thereby achieving the purpose of separating and enriching the target compound.

2. Reverse Phase NH2, Silica, PSA

Uses a non-polar adsorbent (carbohydrate or polymer) on the stationary phase to separate the organic solute from the polar phase (water). The interaction between the non-polar materials is van der Waals attraction (adsorbent’s hydrophobicity).

3. Ion-Exchange SAX, SCX, PAX, PCX,

Ion-exchange SPE cartridges are the separation of ions with high energy interaction. Strongly polar solutes can be separated from highly polar water or other solvents. The exchange capacity of strong ion exchange resins is not affected by pH, and weak ion exchange resins are dependent on pH changes.

For more SPE cartridges details, please contact info@hawach.com

SPE and the SPE Cartridges

As one of the useful sample preparation technique, solid phase extraction can prevent many problems, such as incomplete phase separations, recoveries with poor quantity, waste of expensive fragile glassware, and extra disposal of organic solvents, which you may occur if you use the liquid/liquid extraction.

On the other hand, SPE takes quantitative extractions that are easy to perform with high speed and automated. So it is the more efficient way of extraction than liquid/liquid. To reduce solvent use and lab time, it is often used when we prepare liquid samples, extract semivolatile or nonvolatile analytes, and solid pre-extracted from solvents.

With the advanced extracts purity, SPE is perfect for super complex analyzes. The right choice of SPE cartridges and sorbents will help you achieve the better result. Suitable with many different sorbents, SPE cartridges coincide with the filling materials of HPLC columns, such as reversed phase, normal phase, ion exchange, and the “mixed mode” materials.

The specifications of SPE cartridges we can find is as followed:
Volume: 0.01 ml – 200 ml
Particle Size: 5 µm – 250 µm
Pore Size: 40 Å – 450 Å

What You Should Know About SPE?

Solid-phase extraction is the simple method with digital chromatography compounding either bind or flow through. With solid-phase extraction, many samples can be analyzed almost automated in parallel, but the process may take more time.

Due to its high selectivity, recovery, and reproducibility, SPE methods are widely used for desalting, solvent exchange, sample preservation, and storage.

Compared with the liquid-liquid extraction, the advantages of solid-phase extraction is easy to see. It improves throughput in parallel vs. serial processing, as while as decreases organic solvent usage and waste. It achieves higher and more repeatable recoveries, cleaner extracts from contamination and solvent impurities. The choices of SPE phase and solvent mixtures are always various.

Common applications of solid-phase extraction can be sample cleanup, such as in pharmacokinetic studies, dissolution testing, isolate analytes from complex matrices, such as urine, plasma. It works perfectly but only removing major interferences, but also eliminating late-eluters for the isocratic analysis.

SPE is a reliable method to enrich trace in the environmental analysis, the pharmaceutical and agrochemical applications. It is also practiced widely in processes of desalting, solvent exchange and sample preserve.