Question 1

Can I use autodilution to help in the preparation of standards and samples for ICP-OES and ICP-MS analysis?

Accepted Answer

Yes, autodilution can be used on both ICP-OES and ICP-MS to automate and streamline preparation of calibration standards and perform final sample dilutions. Autodilution systems are also based on valve systems similar to segmented flow introduction systems and are capable of generating different calibration curves (e.g., for drug products with varying daily dosage) from a single stock solution. This reduces the workload for laboratory personnel and also reduces the amount of human interaction with the samples. If a given sample exceeds the calibration range or leads to an internal standard response outside the allowed acceptance criteria, a sample can be automatically diluted and the analysis is repeated. At the same time, autodilution systems are completely integrated into the Qtegra ISDS (https://www.thermofisher.com/order/catalog/product/IQLAAEGABSFAOVMBCZ) operating software, so that all dilution (prescriptive or automatic) steps are documented in a compliant software environment.

Question 2

What is a segmented flow sample introduction system and how can it help me?

Accepted Answer

Segmented flow sample introduction systems are a very helpful tool to increase the productivity in your laboratory. Such devices work with a valve system that enables fast uptake of the sample to the plasma, and minimize the wash out times between different samples. Therefore, the time required for analysis can be shortened considerably. An example for such a system is the sprint valve system available on the Thermo Scientific iCAP 7600 ICP-OES (https://www.thermofisher.com/order/catalog/product/842320076121).

Question 3

Can slurry nebulization be used with pharmaceutical products?

Accepted Answer

Slurry nebulization is more commonly used in environmental testing applications. In principle, slurry nebulization can be used for pharmaceutical testing and there have been studies done on this. Obviously particle size is a key factor here - the smaller the particles the better. However, it is also worth pointing out that the method preferred by USP is microwave digestion.

Question 4

Is it also possible to run samples prepared in organic solvents on an ICP-MS or is it just an option for ICP-OES?

Accepted Answer

It is possible to run samples prepared in organic solvents using ICP-MS. In contrast to ICP-OES, some additional measures have to be taken to achieve optimum performance of the instrument. In particular, the ICP-MS instrument must be fitted with an organics kit which includes a mass flow controller for introducing an Ar/oxygen (O2) mixture into the plasma, to burn up the carbon in the solvent to prevent it from condensing on the cones.

Question 5

How much more difficult is it to use ICP-MS in comparison to ICP-OES?

Accepted Answer

Modern ICP-MS instrumentation has become far easier to operate, both in terms of hardware and software. Furthermore, the advent of intelligent interference removal features such as “low mass cut-off” and kinetic energy discrimination (KED) mode has more or less overcome the need to worry about which settings (cell gas, operation mode, cell operating parameters) are appropriate for which element. Overall, the barrier to success with ICP-MS has been lowered significantly and it should not be viewed as a technically challenging alternative to ICP-OES.

Question 6

When analyzing elemental impurities in phramaceutical samples, how is the method detection limit calculated and how is it related to the parameter instrumental detection limit and blank equivalent concentration?

Accepted Answer

The parameters BEC, LOD, and LOQ are frequently used to describe the detection capabilities of an analytical instrument. The acronym BEC abbreviates the parameter blank equivalent concentration. This value refers to the “apparent concentration”, and is composed of the contamination level in the blank, any residual interference signal, and the instrument background (from the detection system). The parameter instrumental detection limit (IDL, often referred to as Limit of Detection, LOD) is defined as the limit of detection that can be achieved by the instrument used. This amount is typically defined as a quantity that gives a distinguishable signal in the detection system. The common definition for the IDL is based upon the standard deviation (LOD = 3.3 x standard deviation of the regression line of calibration curve) of a blank sample measured in the beginning of a calibration curve, or a minimum signal to noise ratio of 3:1. Both parameters, BEC and IDL are automatically calculated by Thermo Scientific Qtegra Intelligent Scientific Data Solution (ISDS) platform software (https://www.thermofisher.com/order/catalog/product/IQLAAEGABSFAOVMBCZ). In contrast, on the IDL, the parameter method detection limit (MDL) includes the extent of all dilution steps carried out during the sample preparation. The MDL is typically based upon a blank solution that has been prepared according to the preparation procedure that is being used to prepare all the samples. In situations where there is no sample preparation or if the preparation involves a single dilution step, MDLs might be calculated based on the standard deviation of a low level standard. MDL concentrations are always more conservative than IDL concentrations.

Question 7

Is X-ray inspection of pet foods safe?

Accepted Answer

X-ray inspection of packaged and bulk food products is proven to be extremely safe. There is no documented evidence of adverse health effects of X-rays on equipment operators, the food products that travel through the equipment, and ultimately, the pet consuming those products.

Question 8

What is the best inspection technology for wet pet food?

Accepted Answer

Since wet or moist pet foods have a high product effect, X-ray inspection is the best technology to detect contaminants such as metal, glass, stone, and other dense foreign objects.

Question 9

What is the best inspection technology for dry/kibble pet food?

Accepted Answer

Metal detection works very well with dry/kibble pet food and treats that do not have a product effect that wet or moist pet foods do. Metal detection equipment provides reliable, cost-effective protection from even the smallest metal contaminants found in pet food production anywhere in a process. If the packaging material contains metal, X-ray inspection would be the right choice. In addition, if there are other contaminant concerns such as stone, high density plastic or glass, X-ray inspection systems will detect these contaminants as well.

Question 10

Where are the best places on the pet food production line to utilize inspection equipment?

Accepted Answer

There are several points in the pet food production process that benefit from food safety inspection (metal detectors, X-ray inspection) and checkweighing technology. Here are some examples:

- Incoming ingredients. Large pet food producers may require that their vendors meet specific HACCP objectives and provide proof of inspection. Even with those methodologies in place, some will also inspect incoming ingredients. Typical incoming inspection consists of drop through and bulk flow metal detectors.

- After mixing/rendering. Processing equipment such as an industrial blender or mixer will age over time and potentially introduce small particles or shavings of metal into the product being processed. It is important to position inspection equipment after this process equipment to catch any contaminants as early in production as possible, so it doesn't affect final product quality as well as damage equipment further downstream. The inspection equipment type will depend on the product type and whether its formulation creates a “product effect”. Wet or moist pet food products are more suited toward X-ray equipment, while metal detectors perform well with dry or kibble type pet food products.

- After filling/packing. The recommended inspection equipment type is dependent on the packaging material or combination of materials that have been selected for this product. Metal components such as aluminum foil trays, metal cans, aluminum foil bags or metalized firm structures are much more suited to X-ray inspection. Flexible materials without a metal component, paperboard folding cartons, bags or pouches work very well with either metal detectors or X-ray inspection systems. At this stage, checkweighers are frequently used in combination with a metal detector or X-ray inspection system to ensure product weight matches information printed on the product label.

- After case packing. After case packing is another good inspection point as this is the last stop before the finished products leave the facility. The recommended inspection equipment type is dependent on the packaging material of the individual product. This is typically done via X-ray inspection. In addition to contaminant detection, the X-ray system's ability to detect missing pieces will help ensure that the specified count has been loaded into the case. In certain situations, especially when X-ray inspection is not included at the end of the line, checkweighers are placed here to ensure that the proper number of packages are contained inside the case.

Question 11

What is "product effect" in pet food manufacturing?

Accepted Answer

“Product effect” occurs when a product has a conductive property which affects the magnetic field generated by the food metal detector. This is typically found in high salt, high moisture product environments. For example, wet cat food will show significantly more product effect due to its high moisture and salt content. This negatively impacts the metal detector's ability to distinguish between actual non-ferrous metal contaminants and the false signal given by the combination of typical product attributes. In these situations, industrial X-ray inspection equipment will produce significantly better results since product effect is not a factor.

Question 12

Do checkweighers also monitor for physical contaminants?

Accepted Answer

Checkweighers do not detect physical contaminants but they can be combined with food metal detectors and X-ray inspection systems that do detect contaminants. Food metal detection systems provide reliable, cost-effective protection from even the smallest metal contaminants found anywhere in a food production process. Food X-ray inspection systems provide protection from metal, glass, stone and other dense foreign objects for almost any type of packaged, bulk, or piped product.

Food manufacturers can find metallic and non-metallic foreign objects and eliminate “wet” product effects common with metal detectors with the Thermo Scientific NextGuard X-ray Detection Systems (https://www.thermofisher.com/order/catalog/product/NEXTGUARDPRO). Designed for a wide variety of food applications, NextGuard systems offer enhanced capabilities to inspect packaged products for missing pieces or components, under and over-fills, and other quality problems.

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