App Notes & White Papers

Pesticide residues in agricultural food sources are widely considered to cause adverse health effects when consumed by humans. In particular, much of the produce sold in the US is imported and concern over pesticide levels in these fruits and vegetables in comparison to those grown domestically has resulted in increased testing for pesticide residues.

In 2003, the QuEChERS method for pesticide analysis was introduced by Anastassiades and Lehotay et al., and QuEChERS is an acronym for Quick, Easy, Cheap, Effective, Rugged, and Safe. The QuEChERS method allows for analysis of multiple pesticides, while offering faster and easier handling over previous methods. It is now widely used and has been adopted by the AOAC as Method 2007.01 “Determination of Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate.” In Europe, the official standard method is EN 15662.

For a typical analysis, 10 to 15 g samples of chopped and homogenized agricultural produce are placed in 50 mL centrifuge tubes and an extracting solvent, such as acetonitrile, and anhydrous magnesium sulfate and sodium acetate or sodium chloride salts are added. The tubes are capped and shaken by hand for one minute to mix the contents and extract the pesticide into the solvent. The samples are then treated with cleanup materials, concentrated, and analyzed by GC/MS or LC/MS.

In this study, the Geno/Grinder was employed to homogenize the fruit/vegetable samples and to mix the produce rapidly and thoroughly with the salts and solvent in an effort to improve the extraction step. The goal of the study was to determine whether the use of the Geno/Grinder during the extraction step would increase pesticide recovery over the standard, manual QuEChERS method.

In the laboratory, some scientists use manual or semi-automated methods for tissue processing which can be time consuming and produce samples that are not thoroughly homogenized. The implementation of automated homogenization and processing allows for higher throughput of samples, as well as faster and improved recovery of DNA/RNA from biological materials.

This study will demonstrate the efficiency of using an automated homogenization method as a function of time savings, as well as an improvement in the recovery and extraction of genetic material. In previous studies using the Spex Geno/Grinder®, pesticide extraction of agricultural and environmental products was found to greatly increase recovery, while the processing time for sample preparation was significantly reduced.

In this new study (a joint project conducted by Spex and HoppeSyler), a manual pellet mixer and automated homogenizer (Spex Genomax) were used to disrupt a variety of biological tissues prior to genomic DNA (gDNA) isolation. The isolated gDNA was then used for downstream sensitive applications to determine the effectiveness of manual versus automated homogenizers for use in analytical and molecular biology research.

The extraction of nucleic acids (DNA and RNA) is a common practice in molecular biology. The processes used for nucleic acid isolation often result in purified genetic material that can be used in a variety of applications, such as the polymerase chain reaction (PCR) and quantitative PCR (qPCR). These techniques often depend on the purity and quality of the DNA extracted from sample biological tissue in order to produce accurate results. It cannot be understated that the processing of biological tissues prior to DNA isolation plays a critical role in the final result.

Over the last few years, studies have found high levels of contamination in grapes and grape products such as juice and wine. Recent studies have been conducted showing the presence of arsenic in apple juices and wine. Arsenic based pesticides, particularly lead arsenate, were in widespread use around the world up until the late 1980s and 90s. Despite arsenic residue being recognized as a potential problem from the turn of the century, lead arsenate was one of the most widely used pesticides in the nation and was applied to millions of acres of crops through the 1940s. Lead arsenate was the most commonly applied pesticide in fruit orchards, many still in use, so potential for arsenic contamination remains. Heavy metal pesticides were designed to be persistent and can cause environmental and health problems decades after being banned. In this study, samples were obtained of popular organic and regular raisins, sultanas and currants from various stores in the US, UK and Germany. Samples were digested using microwave digestion and testing by ICP-MS to determine heavy metal contamination.

Many popular breakfast and bread spreads are natural products composed of fruits, nuts, seeds, and yeasts. Children are frequent consumers of many of these popular spreads. Studies of individual spread components such as grapes, nuts and cocoa beans have reported significant amounts of heavy metal contamination. Lead arsenate was the most commonly applied pesticide in fruit and nut orchards, many still in use, so potential for arsenic contamination remains. Heavy metal pesticides were designed to be persistent and can cause environmental and health problems decades after being banned. In this study, various samples of bread spreads including fruit spreads, peanut butter, nut butters, yeast spreads, and cocoa spreads were tested for heavy metal contamination. Samples were digested using microwave digestion and testing by ICP-MS to determine possible heavy metal contamination in these common foods.

Food adulteration and counterfeiting continues to grow as a worldwide issue of food safety and economic concern. Spices are one of the most commonly adulterated and counterfeited agricultural products in the US. Our previous study determined extensive elemental and heavy metals contamination and adulteration in spices. Many of our spice products were identified as possibly being highly adulterated or contaminated by metals. In our follow-up organic study, we focused on the organic markers and toxic organic compounds in our common spices and botanicals (black pepper and cinnamon) in various forms (i.e. spices, teas, condiments, and supplements) to determine if tehse products appeared to be adulterated from an organic compound standpoint as well as an elemental standpoint.

Cryogenic grinding and microwave extraction were employed in sample processing. Samples were extracted for the primary and secondary marker compounds native to each spice group and for any potentially toxic organic compounds (dyes, preservatives, pesticides, and industrial residual chemicals). The concentration and identity of compounds were compared across the groupings to cited concentration references for each marker or compound. Low concentrations of critical markers were found in low cost spice and botanical samples indiciating potential adulteration. Samples that were previously suspect by ICP-MS examination were confirmed to be adulterated or economically compromised by reduced or absent concentration of these critical primary and secondary marker compounds. High levels of potentially toxic chemicals were also found in some of the previously suspect spice and spice product samples.

The consumption of botanical products has increased over the past two decades as consumers trend to what are perceived to be natural and high quality botanical products. The primary regions of spice and tea production around the world have often been cited as having less stringent safety and quality standards in regards to consumer products. Products from these regions have been noted to contain a variety of adulterants and contaminants including wear metals and toxic elements.

Common botanicals (black and red pepper, cinnamon, mustard, cumin, and turmeric) sold as spices, teas, condiments, and supplements were purchased at dollar stores, farmers markets, chain stores, and online vitamin outlets. Products selected covered the range of preparations includin gground species, blends, supplement teas and sauces (retail and organic) products. Physical and chemical screening methods were used to detect gross adulteration and counterfeiting. ICP was used to determine macroelement components (Si, Na, Mg, Fe, and K) that indicated possible adulteration or contamination. High levels of bulking agents, including silica and sodium, were often found in low cost spice and botanical samples indicating potential adulteration. ICP-MS was used to determine the presence and level of heavy metal contamination and adulteration. Most of the spice groups studied had many examples of high heavy metals content at the ppm level including very high lead levels which could be indicative of adulteration by lead chromate or lead oxides.

For years, the American Heart Association has recommended eating an average of two to three fishmeals each week to help reduce cholesterol, high blood pressure, and hardening of arteries. Research shows that consuming fish increases high quality protein with fewer calories, and it is rich in omega-3 fatty acids. Omega-3 fatty acid helps to reduce the risk of coronary artery disease, helps in the treatment of bipolar disorder/depression, and helps reduce inflammation in autoimmune diseases (1,4). Fish are also low in sodium and a good source of potassium. Some examples of fatty, coldwater fish that are high in omega-3 fatty acids include salmon, mackerel, and herring.

Unfortunately, due to industrial pollution, many fish have high levels of contaminants including mercury, methyl mercury, and PCBs (polychlorinated biphenyls), which are absorbed by surrounding waters and from foods they eat. Currently, the EPA limit for mercury in fish is 1 ppm. About 22% of all PCBs are in estuarine and coastal sediments, which accounts for 95% of the fish production (2). The EPA estimates up to 15% of mercury emissions from these utilities fall within 30 miles of a plant, and up to 50% falls within six hundred miles. The mercury bio-accumulates through the food chain and reaches the predator species. For example, a Nevada reservoir fish tissue sample shows an average of 0.47 ppm mercury; the EPA guidelines recommend limiting consumption of such fish to one 8-ounce meal per month for adults (3).

For humans, mercury and methyl mercury are toxic and can damage the brain and the nervous system.Mercury poisoning symptoms include numbness in hands and feet, general muscle weakness, and vision, hearing, and speech damage. In extreme cases, insanity, paralysis, coma, and death follow. The U.S. Food and Drug Administration and the EPA advised pregnant women and those who might become pregnant to avoid certain fish known to be high in mercury. This study will investigate trace element concentrations including heavy metal concentrations in different types of fish and fish oil supplements available from local markets in New Jersey. 

The goal of the present study was to examine the phthalate and bisphenol A (BPA) levels of several popular commercial bottled waters in comparison with municipal tap water. In addition, the study attempted to discover whether the phthalate and BPA levels increased after being heated one week at temperatures equivalent to those reached inside an automobile during the summer (60° C). Samples were extracted and tested for phthalate and BPA levels by GC/MS. The concentration of phthalates and BPA found in all the commercially bottled water samples and the municipal water source were either non-existent or well below established guidelines. In addition, the exposure of bottled water to heat did not significantly increase the concentration of phthalates. BPA was not detected in any of the bottled water or municipal water source. 

Chocolate has been harvested for human consumption for thousands of years. The Mayans used cocoa beans as currency. Present day consumption of chocolate is measured on a global scale. In the US, Americans consume over 11 pounds of chocolate per person per year.

Cocoa plants are native to tropical climates with high levels of humidity and rainfall. This climate increases the need for pesticide application to protect the cocoa bean crops. Heavy metals from pesticide and fertilizer applications can accumulate in the soil and add to the possible accumulation of those metals in the cocoa beans.

This study examined the elemental composition of several types of chocolate products from chocolate liquor to milk and dark chocolate bars. 

Evidence of the use of cosmetics, including lipstick, has been found in civilizations as early as ancient Mesopotamia. Many of the cosmetics used throughout history have contained potentially toxic elements and other contaminations. Ancient Egyptians used cosmetics containing large amounts of lead and mercury. Modern cosmetics are perceived to be free of dangerous toxins due the widespread regulation of many consumer products. The FDA, which oversees the regulation of cosmetic products, does not have regulations governing the level of toxic or dangerous contaminants in finished products such as lipsticks.The FDA regulates limits on compound concentrations of additives and colorants but no overall regulation is in place for the finished product’s level of potential contamination.

Studies prior to 2012, have found levels of lead up to 3 ppm in lipstick. The purpose of this study was to re-examine the potential for lead contamination in lipstick and determine if any other potentially toxic metals were present in these lipsticks. Forty-eight lip products including lipsticks, lip glosses, moisturizing sticks, and lip stains were tested for the presence of toxic elements by ICP-MS. 

Salt has been a common commodity and household staple for thousands of years. Over the past decade salt has transformed from common product into a gourmet item with various origins, processing methods, representing all the colors and flavors of the gourmet spice market. Gourmet salt sales exceed $250 million dollars a year. Some exotic varieties are luxury products retailing for more than $20 an ounce compared to regular table salt at $0.02 an ounce.

This study examined a variety of gourmet salts for the elemental composition and for the presence of heavy metals. The salt samples represented many different colors, production methods, textures and price points

Phthalate and bisphenol A (BPA) levels were studied in municipal water straight from the tap and processed through drinking water treatment systems as well as various samples of laboratory water from commercial sources and from deionized (DI) filtration systems. Samples were extracted and tested by GC/MS. The water samples taken directly from municipal tap water had relatively small concentrations of phthalates and BPA but when decanted through consumer Point of-Use (POU) drinking water filtration systems, the level of phthalates and BPA varied greatly depending on the type of system and the amount of water flushed from the system prior to the sample being taken. Laboratory water sources appeared to have the greatest variability on phthalate concentration with LC/MS grade water having the lowest phthalate and BPA concentrations of all the laboratory water. 

The US has started to limit levels of some phthalates for use in children’s’ products including DEHP, DBP, BBP, DINP, DIDP & DIOP. The Consumer Product Safety Commission (CPSC) has published testing methods for these regulated phthalates. The regulation of bisphenol A (BPA) remains under debate. This study examined the levels of phthalates and BPA in 26 children’s toys purchased from local discount or ‘dollar’-type stores. The toys were all reported as being made in China.

Microwave extraction methods were created and optimized against SPEX CertiPrep certified solid reference materials to compare levels of phthalates and BPA found in the toys. Samples were examined using GC/MS. High levels of phthalates and BPA were detected in the majority of the PVC toys. In many samples the concentration of phthalates far exceeded the limits set by the CPSC. 

There are hundreds of commercial pesticides in use in industrial and private agriculture. Concern over the health effects of residual pesticides on fruits and vegetables has led to increased testing of these products to determine the levels of pesticides on produce when it goes to market.

In this study, commercial red wine and beer samples were examined for their pesticide concentrations. In addition to the examination of the finished alcoholic beverage, the constituent agriculture products of wine and beer production (grains, malts hops and wine grapes) were also examined to determine the levels of pesticides found in those products. The sample preparation and extraction process efficiency and recovery were examined by processing samples using manual versus high-throughput techniques. The QuEChERS method was used to process a greater number of samples in a shorter period of time than other extraction methods. 

The consumption of botanical products has increased over the past two decades as consumers trend to what are perceived to be natural and high quality botanical products. The primary regions of spice and tea production around the world have often been cited as having less stringent safety and quality standards in regards to consumer products. Products from these regions have been noted to contain a variety of adulterants and contaminants including wear metals and toxic elements.

The spice samples used were purchased at dollar stores, farmer’s markets, chain stores, and online vitamin outlets. Products included organic products. Cryogenic grinding and microwave digestion were employed in sample processing. ICP-MS was used to determine the presence and level of heavy metal contamination and adulteration. 

The consumption of botanical products has increased over the past two decades as consumers trend to what are perceived to be natural and high quality botanical products. The primary regions of spice and tea production around the world have often been cited as having less stringent safety and quality standards in regards to consumer products. Products from these regions have been noted to contain a variety of adulterants and contaminants including wear metals and toxic elements. The most traded spice in the world is black pepper and accounts for 20% of the world spice market. It is also one of the most commonly adulterated spices on the marketplace with up to 70% of commercial black pepper samples showing some form of adulteration or counterfeiting.

Black pepper samples were purchased at dollar stores, farmers markets, chain stores, and online vitamin outlets. Products selected included both whole black peppercorns and ground black pepper sold as both retail and organic products. Physical and chemical screening methods were used to detect gross adulteration and counterfeiting. ICP was used to determine the macroelement components (Si, Na, Mg, Fe, and K) that indicated possible adulteration or contamination. High levels of bulking agents, including silica and sodium, were often found in low cost spices indicating potential adulteration. ICP-MS was used to determine the presence and level of heavy metal contamination and adulteration. The black pepper samples had many examples of high heavy metals content at the ppm level, including high lead and chromium levels, which could be indicative of adulteration by lead chromate or lead oxides.

The United States Department of Agriculture (USDA) maintains an extensive database of chemical and physical data for food products. These databases show the normal distribution of values of nutritional components for spices. The black pepper samples were compared to the USDA values to determine if their composition was within the normal distribution for a black pepper spice. Many samples were identified with a high probability of adulteration or counterfeiting since they did not fit the spice profile. 

The cannabis industry has taken the world by storm and has flooded the market with new products. Recently, concerns have arisen around the safety of this largely unregulated market. Cannabis testing laboratories emerged to fill the need for specialized testing for cannabinoid potency, pesticides, bacteria/mold and other potential contaminants. Sadly, a significant group of contaminants has been largely ignored: toxic metals.

Recreational cannabis and hemp are both the same species. Federally legal hemp products are easy to obtain by the general public. Hemp products are also used as base for cannabis products & cannabinoid extracts. However, due to a ban on hemp cultivation in the US, virtually all of the hemp used in the US is imported from China, India, Eastern Europe, and Canada. Studies of other commodities exported from these countries have reported widespread heavy metal contamination (i.e. spices, teas, grains, etc.).

Cannabis plants are potential bioaccumulators of heavy metals. In the production of these products, a large amount of plant material is processed to extract concentrates and oils, thereby increasing the risk of heavy metal contamination. The scope of this study was to analyze various legal hemp products, currently on the market, for heavy metal contamination and use hemp as a model for methods development for restricted products. Samples were digested using microwave digestion and analyzed by ICP-OES and ICP-MS.

The consumption of botanical products has increased over the past two decades as consumers trend to what are perceived to be natural and high quality botanical products. The cannabis industry has taken the world by storm and has flooded market with new products. Recently, concerns have arisen around the safety of this largely unregulated market. Cannabis testing laboratories emerged to fill the need for specialized testing for cannabinoid potency, pesticides, bacteria/mold, and other potential contaminants.

Toxic heavy metals are too often found in many common food and health products as well as in our environment. Products which often originate from other countries around the world can be targets for higher contamination, adulteration and counterfeiting with or by heavy metals. The primary regions of spice and tea production around the world have often been cited as having less stringent safety and quality standards in regards to consumer products. Products from these regions have been noted to contain a variety of adulterants and contaminants including wear metals and toxic elements.

Cannabis, potentially, with its mixed legal status, may be poised to become the next crop to be adulterated. Recreational cannabis and hemp are both the same species. Federally, legal hemp products are easy to obtain by the general public. Hemp products are also used as base for cannabis products and cannabinoid extracts. However, due to a ban on hemp cultivation in the US, virtually all of the hemp based in the US is imported from China, India, Eastern Europe, and Canada. Studies of other commodities exported from these countries have reported widespread heavy metal contamination (i.e. spices, teas, grains, etc.).

The scope of this study was to analyze various spice and legal hemp nutraceutical products, currently on the market, for lead contamination and compare those levels to other foodstuff and nutraceutical products examined in past SPEX CertiPrep studies. Samples were digested using microwave digestion and analyzed by ICP-OES and ICP-MS. 

Coffee is a major world commodity with 7 million metric tons of coffee produced annually. Roasted coffee beans can contain well over a thousand different compounds. In most cases, the most important of those chemicals are the flavor compounds (i.e. chlorogenic acids, polyphenols, terpenes, etc.) and caffeine. Other compounds, such as methyl cafestol and homostachydrine, can be important in fingerprinting the authenticity and adulteration of coffee and coffee species. This study created chemical profiles of coffee around targeted groups of chemical markers in coffee to determine: caffeine content (and decaffeination by-products), coffee or species authenticity, and adulteration and safety of coffee using LC/MS. Brewed regular roast and decaffeinated coffee was purchased from multiple chain fast food restaurants, coffee purveyors and convenience stores.

Chemicals which produce flavor or fragrance contain functional groups which activate the corresponding taste receptors to perceive taste which combine with the other senses to produce familiar flavors. 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 a diverse group of compounds responsible for characteristic flavors and fragrances such as citrus, florals, mints, and spices.

The consumption of botanical products has increased over the past two decades as consumers trend to what are perceived to be natural and high quality botanical products. The primary regions of spice and tea production around the world have often been cited as having less stringent safety and quality standards in regards to consumer products. Products from these regions have been noted to contain a variety of adulterants and contaminants including wear metals and toxic elements.

Spices and hot sauces were purchased at dollar stores, farmer’s markets, chain stores, and online. Products included organic products. Cryogenic grinding and microwave digestion were employed in sample processing. ICP-MS was used to determine the presence and level of heavy metal contamination and adulteration.

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 consumption of botanical products has increased over the past two decades as consumers trend to what are perceived to be natural and high quality botanical products. The primary regions of spice and tea production around the world have often been cited as having less stringent safety and quality standards in regards to consumer products. Products from these regions have been noted to contain a variety of adulterants and contaminants including wear metals and toxic elements.

The identification of adulteration, contamination and counterfeiting of food products can be a difficult task. The use of nutritional profiles and detection of adulteration compounds can be useful tools to screen groups of products for further analysis to combat contamination and adulteration.

This study looked at the elemental composition of spices to determine if it was possible to target samples as potentially contaminated or adulterated by the concentration of certain metals (heavy metals, wear metals and nutrient elements). Each metal or elemental group indicates possible sources of adulteration, contamination or counterfeiting. Toxic elements can be found as either contaminants or adulterants. Wear metals can also be considered contaminants, but can cross over into nutrients or additives. In many cases, it is the concentration of a particular element which can move it from a nutrient to an additive.

Over the last few years, studies have found high levels of contamination in grapes and grape products such as juice and wine. Recent studies have been conducted showing the presence of arsenic in apple juices and wine. Arsenic based pesticides, particularly lead arsenate, were in widespread use around the world up until the late 1980’s and 90s. Despite arsenic residue being recognized as a potential problem from the turn of the century, lead arsenate was one of the most widely used pesticides in the nation and was applied to millions of acres of crops through the 1940’s. Lead arsenate was the most commonly applied pesticide in fruit orchards, many still in use, so potential for arsenic contamination remains. Heavy metal pesticides were designed to be persistent and can cause environmental and health problems decades after being banned. Many popular breakfast and bread spreads are natural products composed of fruit, nuts, seeds and yeasts. Children are frequent consumers of many of these popular spreads and dried fruits. Studies of individual spread components such as grapes, nuts and cocoa beans have reported significant amounts of heavy metal contamination. In this study, various samples of dried fruits (including raisins) and bread spreads (including fruit spreads, peanut butter, nut butters, yeast spreads and cocoa spreads) were tested for heavy metal contamination. Samples were digested using microwave digestion and testing by ICP-MS to determine heavy metal contamination possible in these common foods.

In this study, fruit samples were obtained of popular organic and regular raisins, sultanas and currants from various stores in the US, UK and Germany. Spreads obtained were created from different nuts and seeds and purchased from the US, UK and Germany. Samples were digested using microwave digestion and testing by ICP-MS to determine heavy metal contamination, methylmercury were released into the waterways.

The QuEChERS method has been shown to be practical for pesticide analysis on a number of different sample types and is increasingly being employed on more difficult matrices. Unfortunately some matrices either by their nature or their economic value like cannabis can be difficult to analyze with just the QuEChERS method alone. These cannabis samples can show lower recoveries of pesticides and other target analytes than are often observed with more traditional agricultural products. An improved combined extraction and clean-up method is proposed in which both the extraction and dispersive solid phase extraction (DSE) steps are combined and heated using a pressurized fluid extraction and Adding heat and pressure to the process increases the efficiency leading to better sample clean-up and DSE improved analyte recoveries. In this study, a new combined extraction system was optimized to increase sample processing throughput, efficiency and recovery in a one-step process. Different analytes including pesticides, cannabinoids and terpenes were examined to determine improvement of recovery and method efficiency of the combined extraction apparatus. The new method showed marked improvement in sample clean-up, throughput and sample extraction recovery for cannabis testing.

Hard cider or alcoholic cider is an alcohol-fermented beverage produced primarily from apples. Hard ciders have a long history around the world but have only become readily available in the United States over the past two decades. Over the last several years, several studies have been conducted showing the presence of arsenic in apple juices and wine.