Technical Notes

Innovative Reference Materials for Method Validation in Microplastic Analysis Including Interlaboratory Comparison Exercises
Reference materials (RMs) are crucial for validating methods to detect environmental pollutants like microplastics. This study assesses two types of microplastic RMs: dissolvable gelatin capsules and soda tablets, used in international interlaboratory comparison (ILC) studies from 2019 to 2022. The capsules contained various polymers (PET, PVC, PE, PS) in sizes from 50 to 1000 μm, showing RSDs from 0 to 24%. Soda tablets replaced capsules due to their reliability, with RSDs ranging from 8 to 21%. Recovery tests on environmental samples using soda tablets (125–355 μm) showed an RSD of 9%. While larger microplastics could be handled with precision, more work is needed for smaller ones. Nonetheless, this method addresses many challenges in validating microplastic analysis.
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Detection of Staphylococcus aureus using Spex 2-Color qPCR Kit
S. aureus is a ubiquitous gram-positive bacterium that is known to infect plant tissues, as well as the soil. S. aureus infections are known to cause a variety of illnesses in humans, such as endocarditis, deep-seated abscesses, osteomyelitis, bacteraemia, pneumonia, and meningitis (DOI: 10.1111/j.1348- 0421.1995.tb03280.x). Agricultural and nutraceutical products can become contaminated by S. aureus in resulting in human foodborne illnesses. Products such as cannabis, vapes and tobacco can cause S. aureus exposure by direct introduction of contaminated vapors into the respiratory tract.
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Detection of Salmonella Using Spex 2-Color Salmonella Quantitative PCR (qPCR) Kit
There are over 300 million cases of foodborne illnesses in the world each year resulting in almost half a million deaths. Salmonella causes almost 80 million of those illnesses, with several hundred deaths each year. Salmonella are rod-shaped, gram-negative bacteria from the Enterobacteriaceae family. There are two species of Salmonella (S. enterica and S. bongori) with six subspecies and over 2,600 serotypes or strains; some (mostly typhoidal strains) can cause severe illness or death. The 2-Color Salmonella qPCR kit is designed to detect the presence of Salmonella species DNA in tissues of agricultural samples including cannabis products.
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Microorganism Testing in Agricultural and Cannabis Products: Detection of Four Species of Aspergillus Using Spex® 2-Color qPCR Detection Kit
As cannabis becomes legal in more and more states and countries, there has been a corresponding increase in the amount of testing, and the cannabis testing market is currently estimated to reach $1.8 trillion by 2025. Currently, 35 states have legalized its use for medicinal applications, and states continue to pass laws that allow recreational use.

Spex offers products for testing cannabinoids, terpenes, pesticides, residual solvents, mycotoxins, and heavy metals. In this technical note, we will introduce the first of a series of Quantitative Polymerase Chain Reaction (qPCR)-based kits to analyze the number of microorganisms in agricultural products.
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Sample Processing and Preparation for Cannabis Products
Everything about the new cannabis industry is challenging from the actual structure and chemistry of the plant itself down to how samples are chosen and transported for testing. Despite all of the complexity, the approach to sample collection, processing and testing still must remain along the same lines as other similarly complex agricultural products (i.e. hops, spices, etc.). The rational for sampling, processing, grinding, extraction, and testing of these similar products can be used as a road map for the cannabis sampling and processing methods.
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The Differences in Diisononyl Phthalate (DINP)
Phthalates are a heated topic of concern in the analytical field. The regulations and methods from around the world regulate or ban various common phthalate plasticizers have forced analytical laboratories into refining their methods for testing consumer products for these banned or restricted phthalates. The restricted phthalates in children’s toys in the United States include Diethylhexyl phthalate (DEHP), Di-n-butyl phthalate (DBP), Benzylbutyl phthalate (BBP), Di-n-octyl phthalate (DNOP), Diisononyl phthalate (DINP), and Diisodecyl phthalate (DIDP).
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Spiromesifen Summary
Spiromesifen, under normal laboratory use and some conditions (including the presence of acid), can transform from the major product to the major metabolite, Spiromesifen-enol, and additional minor metabolites. Spiromesifen containing standards should be stored in a freezer upon receipt and while not in use. Follow all instructions for use and preparation found on the product certificate. Quantitation of the Spiromesifen is recommended as a sum of both the Spiromesifen product and the enol form. The reported quantitation ions of Spiromesifen and its enol by positive mode LC-MS (ESI) are (M+1) @ 371 m/z (product) and 273 m/z (enol).
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A Technical Guide to Standards, Calibration Curves and Dilutions for the Laboratory User
The reference to standards in a laboratory setting often refers to an actual chemical or physical material called a metrological standard. A metrological standard is the fundamental example or reference for a unit of measure. Simply stated, a standard is the ‘known’ to which an ‘unknown’ can be measured. Metrological standards fall into different hierarchal levels.
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Terpenes: A Building Block of Cannabis
Many chemical compounds can be responsible for scent and flavor in botanicals. These chemicals are transformed into neural impulses and travel along the various facial and major nerves to centers in the brain which then interpret the impulses and create taste perception. These perceptions of taste, along with texture, smell and the sensation associated with temperature, pain and pressure (chemesthesis) combine to create the impressions of flavor.

The most common functional group in flavors is carbonyls such as esters, aldehydes, ketones, etc. Other groups which produce flavors are carbohydrates, acids, salts, proteins, and terpenes. Terpenes are the common term for a large group of compounds that contribute to the flavor and smell of botanical products. Isoprene or 2-methyl-1,3-butadiene (Figure 1) and its polymers is the main base of natural rubber and the structural base for terpenes and terpenoids, even though isoprene is not part of the reactions which produce terpenes.
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The Chemistry of Antiviral Drugs
A virus is a portion of genetic material, protected and transported by complex organic molecules, that can hijack the biochemical processes of a host organism to reproduce itself. Technically they are not alive, but are completely dependent on their host organism to exist and multiply.

Viruses are frequently categorized by the form of the genetic material they carry. Some viruses store their genome in DNA, while others store them in RNA. They are also categorized by the type of proteins that protect them, the shape they adopt, and mechanism of entering cells. COVID-19, for example, is a single-strand RNA virus protected by a phospholipid capsule.
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Structure of Isomers
Isomers are molecules that have the same molecular formula but contain different arrangements of atoms. Depending on how differently the atoms are arranged, isomers can display similar or vastly different properties.

Isomers are organized into two main groups depending on how they differ. Structural isomers are those that have their atoms connected to each other in different ways. In contrast, stereo isomers have the same arrangement of atoms, but occupy 3-dimensional space differently.
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Chemistry of the Sun, Vitamin D and Sunscreen
The sun (or Sol), is at the center of our solar system, and all the planets, asteroids, and other objects are constantly rotating around it, due to its massive gravitational influence. The sun represents 99.86% of the mass of the entire solar system and its size is difficult to comprehend . Its diameter is over 100 times greater, and its mass is more than 300,000 times greater than the Earth’s! If that isn’t mind boggling enough, consider that our sun is actually a small to average sized star compared to some of the largest stars in the universe which can be upwards of 2,000 times larger than the sun (the size difference between an ant and a blue whale!).

The sun is composed of approximately 75% hydrogen and 25% helium. The huge mass of the sun has caused it to contract to its current size, and the enormous pressures at the center has made the sun’s core around 160 times more dense than water. This results in very high pressure which leads to temperatures in the core of roughly 16 million degrees Kelvin. It’s this combination of heat and pressure that fuels the nuclear reactions that produce the sunlight that we need to survive.
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Internal Standards for UV-VIS
Ultraviolet-Visible Spectroscopy (UV-VIS) is a frequently used tool in many fields of chemistry. Its use is central in a wide range of techniques, from simple colorimetric assays to complex biomedical experiments. Many organic or inorganic chemicals absorb light in the range of roughly 200-800 nm, depending on their electronic structure. The technique can be used to confirm the identity of a structure, but it is more frequently used to measure the concentration of substances in a mixture.
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Optimizing Your Mobile Phase: The Importance of Solvent and Buffer
It is important to remember that not all buffers are appropriate for all applications. Salts can precipitate out of solution as mobile phase composition changes. Salts are also problematic for LC/MS analysis since they can inhibit MS detection. If solids are dissolved into mobile phase, it is important to remember to filter the mobile phase and, in some cases, the mobile phase may need to be heated to dissolve solids completely, in which case the column of stationary phase may also have to be kept warm. The totality of factors that enable a good separation of a mixture is called the “method” of the purification. It is important to understand that the first changes during method development often revolve around changes to the chemistry and composition of the mobile phase. There are a lot of different choices which can be made regarding solvent, polarity, modifiers, and chemical conditions which can influence resolution. The best approach is to make changes one at a time and work in a slow, steady pace to optimize all of the parameters of the mobile phase, stationary phase and system to achieve the best method for your analysis.
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What is Accreditation?
Laboratories around the world process and analyze hundreds of thousands of samples each day. Without an assurance of competency and accuracy, those results could be called into question, risking the world’s health, safety and economy. Since the 1940s, the International Organization for Standardization (ISO) has become one of the world’s largest developers of voluntary international standards from all manners of manufactured, agricultural and technological products and services. In the 1990s, ISO began creating standards for laboratories to standardize procedures and ensure competency and accuracy. Through the years, laboratories and reference material providers have pursued ISO accreditation for their facilities as a mark of quality and reliability. Recently, laboratory and reference material standards have been expanded or rewritten. Many established accredited laboratories are now wondering how these recent changes will affect their business. New unaccredited industries and laboratories are trying to understand the standards and the accreditation process in order to prove their own competency and value. In this note, we will look at the most common questions regarding ISO accreditation and how the new changes apply to laboratories and reference material suppliers.
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A Chemist’s Guide to the COVID-19 Outbreak
During this time of heightened anxiety, it is good to know most common laboratory procedures used to keep scientists safe from chemical exposures also work well for limiting biological exposures. More diligence must be paid in common areas and with common touch points in our offices, laboratories and lives. Check on all of the protective equipment used in the laboratory and make sure it is up to the task that is being set. Isolate all potential contaminants and dispose of them quickly. Most importantly, use your knowledge, training and understanding of science to promote calm and educate your coworkers, employees, families, and others of the real facts of infectious diseases and prevention.
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Mold, Fungi and Mycotoxins
Mold and fungi are ubiquitous in the world. Their size and the mobility of their spores cause rapid spread through agricultural products under favorable environmental conditions. Significant crop losses and foodborne illness can be attributed to mold and fungi when secondary metabolites, called mycotoxins, develop. The botanicals, cannabis and food industries battle continuously with such contaminants. In the United States, the CDC estimates that 48 million people get sick from foodborne illnesses, and up to 3,000 die from foodborne diseases each year. More than 250 agents are known to cause foodborne illness and are introduced through contamination, improper handling practices and sanitation. These agents can be chemical, physical or biological.
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Ironing Out the Elements: Essential Nutrients
Animals and plants depend on chemicals and elements on the periodic table to survive. We routinely call these important compounds vitamins and essential nutrients (minerals, fatty acids and amino acids). Most essential nutrients (macro and micronutrients) cannot be synthesized within the organism in sufficient quantities, if at all, for metabolism and must be ingested.

Vitamins are organic molecules that are essential micronutrients organisms needed for proper metabolism. Minerals are chemical elements required as essential nutrients. Essential minerals for an organism are dictated by their classification (plants, animals, etc.). Some species and types of organisms can synthesize certain essential nutrients but may lack the ability to produce others.

Human beings have building block elements such as carbon, hydrogen, oxygen, and nitrogen. Oxygen composes up to 65% of the elements of the body and, together with water, are the primary sources in the human body, which is made up of over 60% water! Carbon accounts for about 18-19% of elements in the body and is the primary key element for organic compounds to build nutrients such as carbohydrates, amino acids, proteins, and nucleic acids. The breakage of carbon bonds is a source of energy in the body. Hydrogen makes up almost 10% of the elements in the body and is another major component in water molecules. Finally, nitrogen is about 3% of the elements of the body and is a key building block or proteins and nucleic acids.
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In Pursuit of the True Value: Error and the Use of Standards in Producing Accurate Data
Analytical laboratories face more challenges and regulations than ever before as accreditation bodies issue increasing numbers of guidelines; and regulatory agencies increase the number of analytes that need to be reported while the levels of detection required decrease. A lot of time, effort and money is invested in deciphering the data and determining its validity and accuracy. Often terms which describe data are used incorrectly or interchangeably to try to validate a data set or methodology (i.e. error vs. uncertainty, precision vs. accuracy, etc). One of the first steps to understanding and validating data is the proper application of appropriate statistics and the understanding of the use and terminology of analytical processes.
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Understanding Measurement and Dilutions
Volumetric measurement is a common, repeated daily activity in most analytical laboratories. Many processes in the laboratory, from sample preparation to standards calculation, depend on accurate and contamination free volumetric measurements. Unfortunately, laboratory volumetric labware, syringes and pipettes are one of the most common sources of contamination, carryover and error in the laboratory.

The most cited sources for dilution and preparation errors stem from improper use and contamination. Improper use means that the volumetric is not used correctly either through mishandling or misunderstanding of the volumetric labware.
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