Holly McCall
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The top 5 questions to ask when investing in accurate mass technology for forensic toxicology workflows

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Are you considering the purchase of a high-resolution accurate mass (HRAM) instrument for your forensic toxicology lab? To help ensure you invest in a solution that ideally meets your needs, ask yourself the following key questions.

1.    How do I ensure my results are based on exemplary data quality?

Certainty in your data quality is ultimately what drives the highest level of confidence in your results, and that certainty is achieved through scan speed and data specificity. The ability to collect rapid MS/MS data increases the quality of the recorded fingerprint you are generating for each sample. For example, the X500R QTOF System from SCIEX has a scan speed of 25 Hz for TOF-MS and 100 Hz when acquiring TOF-MS/MS. With these capabilities, when we run an information dependent acquisition (IDA) scan, we can still achieve low accumulation times and a higher number of candidate hits and also achieve an ideal cycle time for use in reporting quantitative work. In the same way, we can use SWATH® Acquisition from SCIEX to collect MS/MS for all masses throughout the run, but in packets that can be adjusted for your appropriate mass range. These packets help to reduce interferences in a given window by minimizing the precursor masses fragmented at one time instead of simply collecting all mass, all the time, in one window. Running either of these techniques will produce extremely high-quality MS/MS spectra for use in library matching and quantitative workflows, even in the most complex matrices.

2.    What is the ideal acquisition strategy?

Although there are many acquisition options, non-targeted data acquisition can add the most flexibility to your workflows and give you rich data that can help future-proof your lab. A non-targeted acquisition means that you do not specifically identify the compounds of interest during the collection of data, and instead collect data that represents an unbiased, full-picture fingerprint of each specimen. This data can then be processed in multiple ways: (1) using a targeted list, where specified compound chemical formulas are provided for the identification of analytes of interest; or (2) via non-targeted processing, where a blank sample is compared against the unknown sample of interest to identify differentiating peaks that can be evaluated. Since the data is acquired in a non-targeted fashion, users can leverage these processing options to perform retrospective analysis on samples without reacquiring any data. This means that as new and emerging compounds arise, your lab is already positioned with data that allows you to historically identify their prevalence in your area.

3.    How can I simplify the data analysis?

HRAM instruments can produce a lot of information-rich data for analysis. The key to successful implementation and routine operation is quickly, efficiently and consistently distilling that data into results. You can save time in front of the instrument by utilizing automatic data processing. When your batch is complete, the summarized data will be presented for simultaneous identification and quantification. Using customized criteria for pass-fail, which allows for efficient data review, is a critical component of the processing methodology, and is the approach used in the highly intuitive SCIEX OS Software.

4.    Will this instrument handle real samples day after day?

Forensic matrices can be extremely dirty, but extensive sample pretreatment protocols are not always a good fit for a routine lab. A system’s ability to handle large volumes of injections with minimal sample preparation (dilute-and-shoot, crash-and-shoot, etc.) is key to its robustness and longevity. This robustness starts with a proven source designed with orthogonal spray geometry that provides uniform temperature distribution, and optimized counterflow gas delivery that results in efficient ion production while limiting contamination. The stability of the system is further determined by the flight path technology. SCIEX offers the N-optic design with heated TOF path, which yields optimal mass accuracy and resolution over an extended period of time. To further ensure the success of your run, the instrument should have automated calibration, which allows you to check the system calibration at routine intervals throughout your batch acquisition.

5.    How is data storage and file size going to affect my lab?

Data management and storage is a rising and valid concern as labs continue to get more data-rich information. While computers can store much more data today than they could 20 years ago, storing these files on a server comes with a cost, and data movement takes time and can slow scientists’ work. Condensed data files simplify and streamline data storage and portability, although it is critical to achieve this without any losses in data quality, completeness or security.

An HRAM instrument can be a valuable asset to your forensic laboratory. Before you invest in one, make sure you choose the right system and get the most out of it by evaluating each of the 5 questions outlined here.

Holly McCall
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Holly McCall
Holly.McCall@sciex.com

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