Posts by Rachel Kohn
How to use a Moisture Analyzer for Liquid Products
At first it might seem that determining moisture content in liquids is a contradiction in terms. After all, liquids are moisture, right? But think of the difference in taste between a quality brand of vegetable juice and the watered-down taste of a bargain brand. That’s why processors of quality liquid products such as juices and syrups use a moisture analyzer to determine if their product meets their own and industry standards.
Drying ovens to remove excess moisture are part of the processing steps in preparing products such as vegetable juices. But spot-checks using a moisture analyzer should be made prior to packaging. Also called moisture balances, these devices consist of a halogen heater mounted on a precision analytical balance. They are programmed to determine moisture content by the thermogravimetric process and display loss of weight on drying (LOD). “Drying” might seem a misnomer here because the liquid is never fully … Read the rest
Use a Moisture Analyzer for Wood Pellet Quality Control
Wood pellets are becoming more popular as an alternative or supplementary source of heat in many homes and businesses across the land. The Pellet Fuel Institute in October 2011 issued its “Standard Specification for Residential/Commercial Densified Fuel” including recommended moisture content for premium, standard and utility grade wood pellets. A compact moisture analyzer can be used to spot-check moisture content during pellet processing steps.
The Wood Pellet Manufacturing Cycle
A typical 40-pound bag of wood pellets originates as hard- or softwood sawdust, chips, waste materials from furniture and floor manufacturing – virtually any source of wood including trees unsuitable for other uses. The stock is processed to a uniform size with a moisture content of about 13% to 16% prior to the pelletizing operation. Pelletizing is accomplished under high temperatures (~200 ˚F) and pressure (~ 45,000 psi) during which the lignin in the wood serves to bind the particles together … Read the rest
A Vaccine Refrigeration Specification Guide
Proper vaccine refrigeration is not a hit-or-miss proposition. Each year there are reports on how improper vaccine storage or other mishaps relating to vaccines result in loss of potency. This necessitates locating and revaccinating those who have received compromised inoculations plus the associated cost and inconvenience. Proper vaccine storage is also a critical element for complying with government-funded Vaccines for Children (VFC) programs.
Vaccine manufacturers are careful to note the proper storage temperatures for their products along what is called the cold chain of custody between manufacturing and inoculation. But manufacturers have little influence on the equipment used by healthcare facilities to maintain these temperatures. The CDC (Centers for Disease Control and Prevention) has stepped into this by issuing its 2016 Vaccine Storage and Handling Toolkit to provide comprehensive information on this vital activity. The Toolkit also covers in detail the importance of staff training and written standard … Read the rest
How to Check Pump System Accuracy for HPLC Analysis
Pump system accuracy is crucial for equipment used to conduct high performance liquid chromatography (HPLC) analysis in the pharmaceutical and other industries subject to regulatory oversight by the FDA and similar authorities. Among functions performed by HPLC are included checks for purity, monitoring changes in pharmaceutical intermediates during chemical synthesis scale-up, stability and dissolution tests, and performing ongoing quality control procedures.
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A Brief on HPLC Analysis
Identifying an analyte by HPLC is based on accurate and reproducible column retention time as the analyte is pumped through an HPLC system. Reproducible retention time is critical and depends on accurate, uniform, reproducible HPLC pump flow rates.
Note that it is important to distinguish between accuracy and precision. These two terms may seem the same but they are not necessarily so. For example, an HPLC system (or for that matter many other systems such as analytical scales) may … Read the rest
How to Use Moisture Analyzers for Grain & Flour Quality Control
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
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
When to Specify a Flammable Refrigerator
Google refrigerator explosions and chances are you’ll get a lot of hits because of news articles reporting on refrigerator explosions. These events can be spectacular, dangerous and costly. They occur when flammable products are stored in conventional refrigeration units and fumes are ignited by refrigerator electronics such as thermostats, compressors, timers and light switches. A refrigerator for flammable storage is designed to prevent these occurrences. Designs differ from more costly explosion proof refrigerators designed to eliminate the danger of igniting volatile vapors in the laboratory environment.
We agree it is a subtle but important difference. Confusion can occur because most reported refrigerator explosions result when the contents or vapors explode due to an internal ignition source.
Flammable Storage Refrigerator Safety Standards
We’ll start by stating that workarounds do not work when it comes to satisfying NFPA and OSHA guidelines regarding storing … Read the rest
How to Improve Vaccine Storage Temperature Monitoring
Vaccine storage temperature monitoring and reporting are critical requirements for healthcare facilities participating in the Vaccines for Children (VFC) program. Procedures are clearly spelled out in the CDC’s Vaccine Storage and Handling Toolkit.
To comply with these procedures vaccine refrigerators and freezers must be equipped with temperature alarming and recording devices. A temperature logger kit now available from Tovatech can be installed on vaccine storage units that otherwise meet CDC regulations but lack temperature logging and alarming capability.
NIST-Certified Temperature Logger
Supplied with a 5 volt DC power adapter, the compact .75” x 9.25” x 5.5” (HWD) NIST-calibrated DL2 temperature logger kit stores data on a 4GB USB flash drive for retrieval and archiving to a PC or Mac. It is equipped with a backup rechargeable lithium-ion battery that operates the logger for up to 20 hours in the event of a power failure.… Read the rest
Tips for Analytical Balance Weighing Accuracy
Accuracy is a prime if not the prime criterion for analytical balances used in industries such as researching and compounding pharmaceuticals. Analytical balance weighing accuracy is a measure of how close the displayed weight is to the actual weight of samples on the weighing pan.
Two terms apply here. The first is readout, which is the smallest difference in weight that can be read and displayed by the unit. For an analytical balance it is typically 0.1 milligram or 0.001 g. Micro and ultra microbalances can weigh lighter samples.
Accuracy is sometimes confused with precision but it is an incorrect assumption. Precise means that results are consistent. However they may be consistently wrong, and therefore not accurate.
Instead, the second term or criterion to look for is linearity. Linearity is the maximum ± deviation of the displayed sample weight vs. the actual sample weight over the weighing range of the … Read the rest