How to Use Moisture Analyzers for Grain & Flour Quality Control

The KERN MRS moisture analyzer is a professional quality solution to measuring moisture in grains, flours and other food products.
A moisture analyzer is a professional quality solution to measuring moisture in grains, flours and other food products.

Moisture content, defined as the percentage of a product’s weight due to water, is an essential measure of quality control.  A gravimetric moisture analyzer is employed across a broad spectrum of industries to confirm that moisture content is in line with regulations governing a particular industry.

Agricultural products such as grains and the flour derived from grains provide an illustration of where a moisture analyzer is put into play.  A University of Minnesota Extension Report, for example, states that wheat and barley grain must have a moisture content of 13% to 14% for safe storage.  Achieving that target can be costly and time consuming in wet weather.  

When wheat is milled to flour another target applies. A study at the Institute of Food Science and Technology, University of Agriculture, Faisalabad, Pakistan, reports … Read the rest

Stability Testing for Temperature and Humidity

Stability Testing for Temperature and Humidity

Stability testing is a critical part of drug and medicinal product development to determine the shelf life of such products under a variety of environmental conditions such as temperature and humidity.  Family prescriptions likely have on their label a recommended “use by” date and notification if special storage conditions should be observed. The regulatory mandate for stability testing in the United States is contained in 21 CFR Part 211 Section 166.

Tests to determine storage requirements and shelf life for drugs and other medicinal products are taken under a variety of imposed and tightly controlled environmental conditions.  Because testing time can be extensive accelerated studies are permitted to support tentative expiration dates provided full shelf life studies are being conducted.


Temperature and Humidity Test Chamber Specs

Stability testing is performed in specially designed test chambers capable of duplicating a broad range of temperature … Read the rest

Ultrasonic Cavitation vs. Air in an Ultrasonic Cleaner

Ultrasonic cleaning procedures described in our posts nearly always call attention to the importance of degassing fresh cleaning solutions.  Degassing is the process of removing trapped air in liquids.  You can see this by letting a glass of water stand for awhile and note the bubbles that appear on the inside surface.  Trapped, entrained or dissolved, air inhibits cavitation, which is the implosion of micron-size vacuum bubbles that accomplish the cleaning.

Simply operating the equipment for a time, the length of which depends on the volume of cleaning solution, will drive off trapped air. The process can be hastened by a Degas mode on an ultrasonic cleaner. It does the job by switching on and off causing air bubbles to coalesce and allowing them rise to the surface and burst.

Removing Other Air in an Ultrasonic Cleaner

Air can be introduced into an ultrasonic cleaning solution when parts are immersed.  … Read the rest

The Role of a Moisture Analyzer in Manufacturing Fine Wood Furniture

The Kern MLB 50-3N Moisture analyzer from Tovatech is a valuable tool to confirm moisture content in wood.

If your antique family rocking chair or your wood dining chairs start to squeak and wobble chances are the humidity in your home is too low.   On the other hand, if you notice swelling or warping, the atmosphere may be too humid.   This is physical and visual evidence of the importance of moisture content to maintaining fine wood furniture.  It starts with manufacturing, which is why a moisture analyzer is often put to work to verify optimum moisture content before furniture is assembled.

Moisture and Wood

Newly cut wood may have a moisture content of 30%, meaning that 30% of its weight is water.  That’s why anyone splitting cordwood knows that it has to be seasoned before being burned, and that the wood is much lighter after a season in the open air than when it was freshly split.  Seasoning also applies to wood used in construction, and especially in … Read the rest

How to Safely Clean Fine Mesh Sieves

Safely cleaning fine mesh sieves means quickly and thoroughly removing trapped particles without damaging or deforming the sieve mesh.   Manual cleaning using brushes to dislodge particles has drawbacks that include potential damage to fine mesh and failure to achieve 100% particle removal.  The problem is solved by combining the Elma SRH 4/200 rotating sieve holder with a 37 kHz 7.5 gallon Elmasonic E 300H or S 300H ultrasonic cleaner*, all available from Tovatech.


Clean Four Sieves Simultaneously

The electrically powered SRH 4/200 module holds up to 4, 200-mm (8 inch) lab sieves clamped in a slightly canted position and rotates them into and out of the ultrasonic cleaning solution. Ultrasonic cavitation produced by the E or S 300H generator-powered transducers creates billions of minute bubbles that implode vigorously against the screen mesh to quickly but safely dislodge trapped particles.  Because the screens are canted particles fall to the bottom … Read the rest

How to Comply with CDC Vaccine Storage Temperature Monitoring

Digital data logger for vaccine storage
Digital data logger for vaccine storage

One of the recommendations found in the CDC’s Vaccine Storage and Handling Toolkit is the use of digital data loggers along with audio and visual alarms to log internal storage temperatures and sound alarms if temperatures fall outside set limits.  Vaccine storage units that otherwise comply with CDC’s high/low temperature alarm recommendations may not be equipped with the all-important ability to record temperature history.  Instead they rely on personnel manually recording internal temperatures twice daily*.

Vaccine Storage Monitoring Options

Temperature Chart Recorders

Automating temperature monitoring can be achieved with the use of temperature chart recorders.  These are attached by wire to temperature sensors placed in glycerin or glycol-filled bottles positioned in the refrigerator or freezer.  The liquid “insulates” the sensor from spikes that occur when the unit’s door is opened to place or retrieve vaccines and other pharmaceuticals or samples. A disadvantage of paper … Read the rest

Meeting JCAHO Requirements for Refrigerated Storage

Keypad door locks help meet JCAHO requirements for securing samples stored in healthcare organizations’ refrigerators and freezers.  The aim is to control access to lab freezer and lab refrigerator contents while eliminating the risks of keys being lost or duplicated without authorization.  A solution for security departments in healthcare organizations and research labs is the Norlake Secure Guard II™ keypad door lock system.  It is compatible with Nor-Lake glass and solid door scientific refrigerators and freezers as well as certain models from other suppliers.

Secure Guard II, available from Tovatech, provides up to 250 users with access to refrigerated storage units using their existing magstripe ID or proximity ID cards.  Adding and deleting users can be accomplished at the unit.  Stored information is safe due to the non-volatile memory.   An audit trail of the most recent 1500 access attempts provides date, time and user name, and is downloadable via an … Read the rest

How to Maintain a Digital Crane Scale

A digital crane scale, while ruggedly constructed to perform heavy lifting and weighing functions, is also a precision instrument that must be maintained on a regular basis.  While maintenance is important for any weighing instrument from an accuracy standpoint, heavy-duty crane scales must be checked regularly to avoid a mechanical failure that could cause a load to drop with potential disastrous results.

Crane scale manufacturers such as Kern, whose products are offered by Tovatech, provide maintenance instructions as part of their operations manuals.  We’ll use here as an example the Kern HTS industrial hanging scale available in four models with maximum weight capacities from 1500 to 10,000 kg (~3,300 to 22,000 pounds)  The scale is powered by a rechargeable battery and is shipped with an infrared, battery-powered remote control with a range of approximately 25 feet.

Crane Scale Maintenance Guidelines

Key lifting components on crane scales include shackles, hooks and … Read the rest

How to Prepare Samples Rapidly and Safely

Sample preparation to transform analytes into measurable form can involve complex processes. It is important that the transformation or extraction process avoids chemical degradation that can be caused by excessive heat or mechanically induced damage.

Ultrasonic energy is a proven technique to achieve fast, safe sample preparation.  As an example it is a method often specified in USP monographs to extract active pharmaceutical ingredients from carriers for content uniformity and potency assay tests. The ultrasonic process is also ideal for dissolving, dispersing, emulsifying, homogenizing and mixing.

Sample Preparation Steps

Samples to be analyzed are placed in flasks along with a recommended solvent.  Flasks are partially immersed in a sonicator bath containing a surfactant.   The 37 kHz Elmasonic S150 ultrasonic bath available from Tovatech is especially designed to quickly and safely accomplish sample preparation.  The inside dimensions of the shallow basket, (LxWxH) 17.9 x 9.8 x 2.2 inches, facilitate positioning of … Read the rest

How to Simplify Accuracy Checks on HPLC Pump Systems

Eluent passing through HPLC pump systems can, over time, impact the accuracy of the system and result in inaccurate flow rates.  HPLC pump system impellers, valves, seals, injectors and other components in direct contact with analytes carried in an eluent are subject to wear as well as possible deposition of damaging salts and other substances that interfere with flow rates.

That’s why HPLC pump system flow rates should be checked on a regular basis.  Regular accuracy checks contribute to meeting FDA standards for system OQ and PQ validation as well as ongoing performance verification.  There are different ways to do this.  One we call the hard way, the other the easy way.

An example of the hard way is repeatedly and manually collecting and measuring by weight or volume the solvent as it exits the HPLC system.  This is extremely work-intensive and highly subject to operator error.

An easier and … Read the rest