Chemists frequently encounter problems associated with trace palladium in synthetic samples because palladium is widely used in synthetic organic chemistry. We previously reported a colorimetric method for trace palladium quantification, the only high-throughput method implemented in the pharmaceutical industry. However, slight changes from the published reaction conditions have caused reproducibility problems, with little understanding of underlying molecular mechanisms. In the current study, we took a combinatorial approach to investigate the method and found that excess NaOH was a culprit for the lack of reproducibility. We changed the reaction conditions and procedure accordingly, which substantially improved reproducibility. The reaction under current conditions followed Michaelis–Menten kinetics, allowing for predicting reaction rates on the basis of the substrate concentrations. The current method showed 57 and 72% average error, respectively, when drugs spiked with known amounts of palladium and synthetic samples with unknown amounts of palladium were analyzed. The trend of palladium concentrations determined by the current method boded well with actual palladium concentrations.

Background Adverse airway events (AAEs) are rare but devastating complications following palatoplasty. The purpose of this study is to evaluate patient risk factors for their effect on these complications. We hypothesize that prolonged operative time and the presence of multiple medical comorbidities are risk factors for AAEs. Design Retrospective cohort study. Setting Participant hospitals in the Pediatric American College of Surgeons National Surgical Quality Improvement Program year 2016–2019. Patients Cases of palatoplasty in children under 3 years of age. Outcomes Adverse airway events including postoperative reintubation or any requirement of postoperative mechanical ventilation. Results A total of 6668 patients met inclusion criteria. The median operative time was 126 min (IQR 82). AAEs were identified in 107 (1.6%) patients. The incidence of risk factors was found to increase with age and AAEs were more prevalent in younger and older patients. Although patients in the older age groups had significantly higher burden of comorbidities, differences in age were not independently associated with AAEs. Following multivariable logistic regressions, operative times greater than 2 h, ASA class ≥3, >3 medical comorbidities, and black race were found to be significant independent risk factors. Conclusions In this large, retrospective database study in palatoplasty, increased operative time, ASA classification ≥3, multiple comorbidities, and black race were independently associated with AAEs.

Chemists frequently encounter problems associated with trace palladium in synthetic samples because palladium is presumably the most frequently used transition metal in synthetic organic chemistry. We previously reported a colorimetric method for trace palladium quantification, the only high throughput method implemented in the pharmaceutical industry. However, slight changes from the published reaction conditions have caused reproducibility problems, with little understanding of underlying molecular mechanisms. In the current study, we took a combinatorial approach to investigate the method and found that strong basicity was a culprit for the lack of reproducibility. We changed the reaction conditions and procedure accordingly, which substantially improved reproducibility. We discovered that the reaction followed Michaelis-Menten kinetics, allowing for predicting reaction rates on the basis of the substrate concentrations. The current method showed good correlation with inductively coupled plasma mass spectroscopy when 14 synthetic samples with unknown amounts of trace palladium were quantified.

Chemists frequently encounter problems associated with trace palladium in synthetic samples because palladium is presumably the most frequently used transition metal in synthetic organic chemistry. We previously reported a colorimetric method for trace palladium quantification, the only high throughput method implemented in the pharmaceutical industry. However, slight changes from the published reaction conditions have caused reproducibility problems, with little understanding of underlying molecular mechanisms. In the current study, we took a combinatorial approach to investigate the method and found that strong basicity was a culprit for the lack of reproducibility. We changed the reaction conditions and procedure accordingly, which substantially improved reproducibility. We discovered that the reaction followed Michaelis-Menten kinetics, allowing for predicting reaction rates on the basis of the substrate concentrations. The current method showed good correlation with inductively coupled plasma mass spectroscopy when 14 synthetic samples with unknown amounts of trace palladium were quantified.