What’s the Difference Between LC-MS and GC-MS?

If you’re wondering what the difference is between an LC-MS and a GC-MS, you’ve come to the right place. These methods are used in toxicology laboratories to identify substances that are harmful to human health and the environment. However, they differ greatly in their abilities to determine the effects of drugs and other chemicals. Learn more about these methods by reading this article. It also lists the legal statutes and administrative codes that govern these tests.


LC-MS is a rapidly growing technology in clinical toxicology  Toxicology Lab laboratories. The need for comprehensive, constantly updated databases and reliable methods for testing psychoactive and other substances is unceasing. With the rapid introduction of new psychoactive and other substances, reducing false positives and negatives will save time and money. Users of multichannel LC-MS systems will be particularly interested in how to increase throughput. Toxicology labs can dramatically increase their capacity and speed with this technology.

LC-MS-MS can identify 52 analytes from urine, including those from both illicit and prescription drug classes. The method is easily amended to detect NPS compounds, making it a versatile alternative to ELISA. Its fast turnaround time, low cost, and high sensitivity make it an excellent choice for routine casework. However, some substances may not be visible with this method. LC-MS is a powerful tool that has the potential to replace ELISA panels.

The LC-MS/MS technique is not the perfect solution for all laboratory tests. There are many challenges to the accuracy of the measurements, including the lack of standardization. Nevertheless, the lack of standardization has led to the development of standardized methods for vitamin D and testosterone. The Endocrine Society and the Centers for Disease Control and Prevention (CDC) have collaborated to create standardized tests for these compounds.

The validation of a multitarget assay method was performed in a case study in which a compound was identified that was not detected by basic drug screening. This method enables the laboratory to screen for 68 different substances and more than double the sensitivity of the immunoassays. In addition, the multi-target methodology is customizable and can be customized to suit the needs of the laboratory. In the present study, the authors have validated this method for several NPS compounds.

To evaluate the cost-effectiveness of LC-MS in toxicology labs, a comprehensive cost analysis is required. The comparison between methods should consider the cost of consumables, such as analytical columns, deuterated internal standards, and instrument pipettes. The cost of these consumables depends on the number of cases analyzed and the cost of certified reference standards. A laboratory’s overall costs should be weighed against the cost of the test.

A two-plate automated ELISA system is used in the laboratory. This allows up to 20 cases to be analyzed simultaneously. The laboratory also has seven ELISA assays running simultaneously. Using these methods would take six and a half hours respectively. Assuming these two methods were used for the same test, the laboratory would spend six hours analyzing 20 cases and twenty controls. The latter is a far superior method, based on the number of analytes detected.